diff --git a/src/main/java/roomescape/RoomescapeApplication.kt b/src/main/kotlin/roomescape/RoomescapeApplication.kt
similarity index 100%
rename from src/main/java/roomescape/RoomescapeApplication.kt
rename to src/main/kotlin/roomescape/RoomescapeApplication.kt
diff --git a/src/main/java/roomescape/auth/docs/AuthAPI.kt b/src/main/kotlin/roomescape/auth/docs/AuthAPI.kt
similarity index 100%
rename from src/main/java/roomescape/auth/docs/AuthAPI.kt
rename to src/main/kotlin/roomescape/auth/docs/AuthAPI.kt
diff --git a/src/main/java/roomescape/auth/infrastructure/jwt/JwtHandler.kt b/src/main/kotlin/roomescape/auth/infrastructure/jwt/JwtHandler.kt
similarity index 100%
rename from src/main/java/roomescape/auth/infrastructure/jwt/JwtHandler.kt
rename to src/main/kotlin/roomescape/auth/infrastructure/jwt/JwtHandler.kt
diff --git a/src/main/java/roomescape/auth/service/AuthService.kt b/src/main/kotlin/roomescape/auth/service/AuthService.kt
similarity index 100%
rename from src/main/java/roomescape/auth/service/AuthService.kt
rename to src/main/kotlin/roomescape/auth/service/AuthService.kt
diff --git a/src/main/java/roomescape/auth/web/AuthController.kt b/src/main/kotlin/roomescape/auth/web/AuthController.kt
similarity index 100%
rename from src/main/java/roomescape/auth/web/AuthController.kt
rename to src/main/kotlin/roomescape/auth/web/AuthController.kt
diff --git a/src/main/java/roomescape/auth/web/AuthDTO.kt b/src/main/kotlin/roomescape/auth/web/AuthDTO.kt
similarity index 100%
rename from src/main/java/roomescape/auth/web/AuthDTO.kt
rename to src/main/kotlin/roomescape/auth/web/AuthDTO.kt
diff --git a/src/main/java/roomescape/auth/web/support/AuthAnnotations.kt b/src/main/kotlin/roomescape/auth/web/support/AuthAnnotations.kt
similarity index 100%
rename from src/main/java/roomescape/auth/web/support/AuthAnnotations.kt
rename to src/main/kotlin/roomescape/auth/web/support/AuthAnnotations.kt
diff --git a/src/main/java/roomescape/auth/web/support/AuthInterceptors.kt b/src/main/kotlin/roomescape/auth/web/support/AuthInterceptors.kt
similarity index 100%
rename from src/main/java/roomescape/auth/web/support/AuthInterceptors.kt
rename to src/main/kotlin/roomescape/auth/web/support/AuthInterceptors.kt
diff --git a/src/main/java/roomescape/auth/web/support/CookieUtils.kt b/src/main/kotlin/roomescape/auth/web/support/CookieUtils.kt
similarity index 100%
rename from src/main/java/roomescape/auth/web/support/CookieUtils.kt
rename to src/main/kotlin/roomescape/auth/web/support/CookieUtils.kt
diff --git a/src/main/java/roomescape/auth/web/support/MemberIdResolver.kt b/src/main/kotlin/roomescape/auth/web/support/MemberIdResolver.kt
similarity index 100%
rename from src/main/java/roomescape/auth/web/support/MemberIdResolver.kt
rename to src/main/kotlin/roomescape/auth/web/support/MemberIdResolver.kt
diff --git a/src/main/java/roomescape/common/config/JacksonConfig.kt b/src/main/kotlin/roomescape/common/config/JacksonConfig.kt
similarity index 100%
rename from src/main/java/roomescape/common/config/JacksonConfig.kt
rename to src/main/kotlin/roomescape/common/config/JacksonConfig.kt
diff --git a/src/main/java/roomescape/common/config/SwaggerConfig.kt b/src/main/kotlin/roomescape/common/config/SwaggerConfig.kt
similarity index 100%
rename from src/main/java/roomescape/common/config/SwaggerConfig.kt
rename to src/main/kotlin/roomescape/common/config/SwaggerConfig.kt
diff --git a/src/main/java/roomescape/common/config/WebMvcConfig.kt b/src/main/kotlin/roomescape/common/config/WebMvcConfig.kt
similarity index 100%
rename from src/main/java/roomescape/common/config/WebMvcConfig.kt
rename to src/main/kotlin/roomescape/common/config/WebMvcConfig.kt
diff --git a/src/main/java/roomescape/common/dto/response/CommonApiResponse.kt b/src/main/kotlin/roomescape/common/dto/response/CommonApiResponse.kt
similarity index 100%
rename from src/main/java/roomescape/common/dto/response/CommonApiResponse.kt
rename to src/main/kotlin/roomescape/common/dto/response/CommonApiResponse.kt
diff --git a/src/main/java/roomescape/common/exception/ErrorType.kt b/src/main/kotlin/roomescape/common/exception/ErrorType.kt
similarity index 100%
rename from src/main/java/roomescape/common/exception/ErrorType.kt
rename to src/main/kotlin/roomescape/common/exception/ErrorType.kt
diff --git a/src/main/java/roomescape/common/exception/ExceptionControllerAdvice.kt b/src/main/kotlin/roomescape/common/exception/ExceptionControllerAdvice.kt
similarity index 94%
rename from src/main/java/roomescape/common/exception/ExceptionControllerAdvice.kt
rename to src/main/kotlin/roomescape/common/exception/ExceptionControllerAdvice.kt
index 7816c443..1f892236 100644
--- a/src/main/java/roomescape/common/exception/ExceptionControllerAdvice.kt
+++ b/src/main/kotlin/roomescape/common/exception/ExceptionControllerAdvice.kt
@@ -5,11 +5,9 @@ import io.github.oshai.kotlinlogging.KotlinLogging
 import org.springframework.http.HttpStatus
 import org.springframework.http.ResponseEntity
 import org.springframework.http.converter.HttpMessageNotReadableException
-import org.springframework.web.HttpRequestMethodNotSupportedException
 import org.springframework.web.bind.MethodArgumentNotValidException
 import org.springframework.web.bind.annotation.ExceptionHandler
 import org.springframework.web.bind.annotation.RestControllerAdvice
-import org.springframework.web.client.ResourceAccessException
 import roomescape.common.dto.response.CommonErrorResponse
 
 @RestControllerAdvice
diff --git a/src/main/java/roomescape/common/exception/RoomescapeException.kt b/src/main/kotlin/roomescape/common/exception/RoomescapeException.kt
similarity index 100%
rename from src/main/java/roomescape/common/exception/RoomescapeException.kt
rename to src/main/kotlin/roomescape/common/exception/RoomescapeException.kt
diff --git a/src/main/java/roomescape/member/business/MemberService.kt b/src/main/kotlin/roomescape/member/business/MemberService.kt
similarity index 100%
rename from src/main/java/roomescape/member/business/MemberService.kt
rename to src/main/kotlin/roomescape/member/business/MemberService.kt
diff --git a/src/main/java/roomescape/member/docs/MemberAPI.kt b/src/main/kotlin/roomescape/member/docs/MemberAPI.kt
similarity index 100%
rename from src/main/java/roomescape/member/docs/MemberAPI.kt
rename to src/main/kotlin/roomescape/member/docs/MemberAPI.kt
diff --git a/src/main/java/roomescape/member/infrastructure/persistence/MemberEntity.kt b/src/main/kotlin/roomescape/member/infrastructure/persistence/MemberEntity.kt
similarity index 100%
rename from src/main/java/roomescape/member/infrastructure/persistence/MemberEntity.kt
rename to src/main/kotlin/roomescape/member/infrastructure/persistence/MemberEntity.kt
diff --git a/src/main/java/roomescape/member/infrastructure/persistence/MemberRepository.kt b/src/main/kotlin/roomescape/member/infrastructure/persistence/MemberRepository.kt
similarity index 100%
rename from src/main/java/roomescape/member/infrastructure/persistence/MemberRepository.kt
rename to src/main/kotlin/roomescape/member/infrastructure/persistence/MemberRepository.kt
diff --git a/src/main/java/roomescape/member/web/MemberController.kt b/src/main/kotlin/roomescape/member/web/MemberController.kt
similarity index 100%
rename from src/main/java/roomescape/member/web/MemberController.kt
rename to src/main/kotlin/roomescape/member/web/MemberController.kt
diff --git a/src/main/java/roomescape/member/web/MemberDTO.kt b/src/main/kotlin/roomescape/member/web/MemberDTO.kt
similarity index 100%
rename from src/main/java/roomescape/member/web/MemberDTO.kt
rename to src/main/kotlin/roomescape/member/web/MemberDTO.kt
diff --git a/src/main/java/roomescape/payment/business/PaymentService.kt b/src/main/kotlin/roomescape/payment/business/PaymentService.kt
similarity index 99%
rename from src/main/java/roomescape/payment/business/PaymentService.kt
rename to src/main/kotlin/roomescape/payment/business/PaymentService.kt
index 0b9093c9..a7343ef8 100644
--- a/src/main/java/roomescape/payment/business/PaymentService.kt
+++ b/src/main/kotlin/roomescape/payment/business/PaymentService.kt
@@ -54,7 +54,6 @@ class PaymentService(
             canceledAt = cancelInfo.canceledAt
     ).also { canceledPaymentRepository.save(it) }
 
-
     @Transactional
     fun createCanceledPaymentByReservationId(reservationId: Long): PaymentCancelRequest {
         val paymentKey: String = paymentRepository.findPaymentKeyByReservationId(reservationId)
diff --git a/src/main/java/roomescape/payment/infrastructure/client/PaymentCancelResponseDeserializer.kt b/src/main/kotlin/roomescape/payment/infrastructure/client/PaymentCancelResponseDeserializer.kt
similarity index 100%
rename from src/main/java/roomescape/payment/infrastructure/client/PaymentCancelResponseDeserializer.kt
rename to src/main/kotlin/roomescape/payment/infrastructure/client/PaymentCancelResponseDeserializer.kt
diff --git a/src/main/java/roomescape/payment/infrastructure/client/PaymentConfig.kt b/src/main/kotlin/roomescape/payment/infrastructure/client/PaymentConfig.kt
similarity index 100%
rename from src/main/java/roomescape/payment/infrastructure/client/PaymentConfig.kt
rename to src/main/kotlin/roomescape/payment/infrastructure/client/PaymentConfig.kt
diff --git a/src/main/java/roomescape/payment/infrastructure/client/PaymentProperties.kt b/src/main/kotlin/roomescape/payment/infrastructure/client/PaymentProperties.kt
similarity index 100%
rename from src/main/java/roomescape/payment/infrastructure/client/PaymentProperties.kt
rename to src/main/kotlin/roomescape/payment/infrastructure/client/PaymentProperties.kt
diff --git a/src/main/java/roomescape/payment/infrastructure/client/TossPaymentClient.kt b/src/main/kotlin/roomescape/payment/infrastructure/client/TossPaymentClient.kt
similarity index 100%
rename from src/main/java/roomescape/payment/infrastructure/client/TossPaymentClient.kt
rename to src/main/kotlin/roomescape/payment/infrastructure/client/TossPaymentClient.kt
diff --git a/src/main/java/roomescape/payment/infrastructure/client/TossPaymentDTO.kt b/src/main/kotlin/roomescape/payment/infrastructure/client/TossPaymentDTO.kt
similarity index 100%
rename from src/main/java/roomescape/payment/infrastructure/client/TossPaymentDTO.kt
rename to src/main/kotlin/roomescape/payment/infrastructure/client/TossPaymentDTO.kt
diff --git a/src/main/java/roomescape/payment/infrastructure/persistence/CanceledPaymentEntity.kt b/src/main/kotlin/roomescape/payment/infrastructure/persistence/CanceledPaymentEntity.kt
similarity index 100%
rename from src/main/java/roomescape/payment/infrastructure/persistence/CanceledPaymentEntity.kt
rename to src/main/kotlin/roomescape/payment/infrastructure/persistence/CanceledPaymentEntity.kt
diff --git a/src/main/java/roomescape/payment/infrastructure/persistence/CanceledPaymentRepository.kt b/src/main/kotlin/roomescape/payment/infrastructure/persistence/CanceledPaymentRepository.kt
similarity index 100%
rename from src/main/java/roomescape/payment/infrastructure/persistence/CanceledPaymentRepository.kt
rename to src/main/kotlin/roomescape/payment/infrastructure/persistence/CanceledPaymentRepository.kt
diff --git a/src/main/java/roomescape/payment/infrastructure/persistence/PaymentEntity.kt b/src/main/kotlin/roomescape/payment/infrastructure/persistence/PaymentEntity.kt
similarity index 100%
rename from src/main/java/roomescape/payment/infrastructure/persistence/PaymentEntity.kt
rename to src/main/kotlin/roomescape/payment/infrastructure/persistence/PaymentEntity.kt
diff --git a/src/main/java/roomescape/payment/infrastructure/persistence/PaymentRepository.kt b/src/main/kotlin/roomescape/payment/infrastructure/persistence/PaymentRepository.kt
similarity index 100%
rename from src/main/java/roomescape/payment/infrastructure/persistence/PaymentRepository.kt
rename to src/main/kotlin/roomescape/payment/infrastructure/persistence/PaymentRepository.kt
diff --git a/src/main/java/roomescape/payment/web/PaymentDTO.kt b/src/main/kotlin/roomescape/payment/web/PaymentDTO.kt
similarity index 100%
rename from src/main/java/roomescape/payment/web/PaymentDTO.kt
rename to src/main/kotlin/roomescape/payment/web/PaymentDTO.kt
diff --git a/src/main/java/roomescape/reservation/business/ReservationService.kt b/src/main/kotlin/roomescape/reservation/business/ReservationService.kt
similarity index 99%
rename from src/main/java/roomescape/reservation/business/ReservationService.kt
rename to src/main/kotlin/roomescape/reservation/business/ReservationService.kt
index efc7c950..c263ac45 100644
--- a/src/main/java/roomescape/reservation/business/ReservationService.kt
+++ b/src/main/kotlin/roomescape/reservation/business/ReservationService.kt
@@ -98,7 +98,6 @@ class ReservationService(
                 reservationRepository.save(it)
             }.toRetrieveResponse()
 
-
     private fun validateMemberAlreadyReserve(themeId: Long?, timeId: Long?, date: LocalDate?, memberId: Long?) {
         val spec: Specification<ReservationEntity> = ReservationSearchSpecification()
                 .sameMemberId(memberId)
diff --git a/src/main/java/roomescape/reservation/business/ReservationWithPaymentService.kt b/src/main/kotlin/roomescape/reservation/business/ReservationWithPaymentService.kt
similarity index 99%
rename from src/main/java/roomescape/reservation/business/ReservationWithPaymentService.kt
rename to src/main/kotlin/roomescape/reservation/business/ReservationWithPaymentService.kt
index 5353285d..2125db1e 100644
--- a/src/main/java/roomescape/reservation/business/ReservationWithPaymentService.kt
+++ b/src/main/kotlin/roomescape/reservation/business/ReservationWithPaymentService.kt
@@ -49,7 +49,6 @@ class ReservationWithPaymentService(
     @Transactional(readOnly = true)
     fun isNotPaidReservation(reservationId: Long): Boolean = !paymentService.isReservationPaid(reservationId)
 
-
     fun updateCanceledTime(
             paymentKey: String,
             canceledAt: OffsetDateTime
diff --git a/src/main/java/roomescape/reservation/business/TimeService.kt b/src/main/kotlin/roomescape/reservation/business/TimeService.kt
similarity index 99%
rename from src/main/java/roomescape/reservation/business/TimeService.kt
rename to src/main/kotlin/roomescape/reservation/business/TimeService.kt
index b3b6bb9e..48486d02 100644
--- a/src/main/java/roomescape/reservation/business/TimeService.kt
+++ b/src/main/kotlin/roomescape/reservation/business/TimeService.kt
@@ -27,7 +27,6 @@ class TimeService(
                     HttpStatus.BAD_REQUEST
             )
 
-
     @Transactional(readOnly = true)
     fun findAll(): TimeRetrieveListResponse = timeRepository.findAll().toRetrieveListResponse()
 
diff --git a/src/main/java/roomescape/reservation/docs/ReservationAPI.kt b/src/main/kotlin/roomescape/reservation/docs/ReservationAPI.kt
similarity index 100%
rename from src/main/java/roomescape/reservation/docs/ReservationAPI.kt
rename to src/main/kotlin/roomescape/reservation/docs/ReservationAPI.kt
diff --git a/src/main/java/roomescape/reservation/docs/TimeAPI.kt b/src/main/kotlin/roomescape/reservation/docs/TimeAPI.kt
similarity index 100%
rename from src/main/java/roomescape/reservation/docs/TimeAPI.kt
rename to src/main/kotlin/roomescape/reservation/docs/TimeAPI.kt
index bbb738c3..939c1522 100644
--- a/src/main/java/roomescape/reservation/docs/TimeAPI.kt
+++ b/src/main/kotlin/roomescape/reservation/docs/TimeAPI.kt
@@ -12,10 +12,10 @@ import org.springframework.web.bind.annotation.RequestParam
 import roomescape.auth.web.support.Admin
 import roomescape.auth.web.support.LoginRequired
 import roomescape.common.dto.response.CommonApiResponse
-import roomescape.reservation.web.TimeWithAvailabilityListResponse
 import roomescape.reservation.web.TimeCreateRequest
 import roomescape.reservation.web.TimeCreateResponse
 import roomescape.reservation.web.TimeRetrieveListResponse
+import roomescape.reservation.web.TimeWithAvailabilityListResponse
 import java.time.LocalDate
 
 @Tag(name = "4. 예약 시간 API", description = "예약 시간을 조회 / 추가 / 삭제할 때 사용합니다.")
diff --git a/src/main/java/roomescape/reservation/infrastructure/persistence/ReservationEntity.kt b/src/main/kotlin/roomescape/reservation/infrastructure/persistence/ReservationEntity.kt
similarity index 96%
rename from src/main/java/roomescape/reservation/infrastructure/persistence/ReservationEntity.kt
rename to src/main/kotlin/roomescape/reservation/infrastructure/persistence/ReservationEntity.kt
index 37dfbd84..a81cda62 100644
--- a/src/main/java/roomescape/reservation/infrastructure/persistence/ReservationEntity.kt
+++ b/src/main/kotlin/roomescape/reservation/infrastructure/persistence/ReservationEntity.kt
@@ -1,7 +1,6 @@
 package roomescape.reservation.infrastructure.persistence
 
 import com.fasterxml.jackson.annotation.JsonIgnore
-import io.swagger.v3.oas.annotations.media.Schema
 import jakarta.persistence.*
 import roomescape.member.infrastructure.persistence.MemberEntity
 import roomescape.theme.infrastructure.persistence.ThemeEntity
diff --git a/src/main/java/roomescape/reservation/infrastructure/persistence/ReservationRepository.kt b/src/main/kotlin/roomescape/reservation/infrastructure/persistence/ReservationRepository.kt
similarity index 100%
rename from src/main/java/roomescape/reservation/infrastructure/persistence/ReservationRepository.kt
rename to src/main/kotlin/roomescape/reservation/infrastructure/persistence/ReservationRepository.kt
diff --git a/src/main/java/roomescape/reservation/infrastructure/persistence/ReservationSearchSpecification.kt b/src/main/kotlin/roomescape/reservation/infrastructure/persistence/ReservationSearchSpecification.kt
similarity index 100%
rename from src/main/java/roomescape/reservation/infrastructure/persistence/ReservationSearchSpecification.kt
rename to src/main/kotlin/roomescape/reservation/infrastructure/persistence/ReservationSearchSpecification.kt
diff --git a/src/main/java/roomescape/reservation/infrastructure/persistence/TimeEntity.kt b/src/main/kotlin/roomescape/reservation/infrastructure/persistence/TimeEntity.kt
similarity index 100%
rename from src/main/java/roomescape/reservation/infrastructure/persistence/TimeEntity.kt
rename to src/main/kotlin/roomescape/reservation/infrastructure/persistence/TimeEntity.kt
diff --git a/src/main/java/roomescape/reservation/infrastructure/persistence/TimeRepository.kt b/src/main/kotlin/roomescape/reservation/infrastructure/persistence/TimeRepository.kt
similarity index 100%
rename from src/main/java/roomescape/reservation/infrastructure/persistence/TimeRepository.kt
rename to src/main/kotlin/roomescape/reservation/infrastructure/persistence/TimeRepository.kt
diff --git a/src/main/java/roomescape/reservation/web/ReservationController.kt b/src/main/kotlin/roomescape/reservation/web/ReservationController.kt
similarity index 100%
rename from src/main/java/roomescape/reservation/web/ReservationController.kt
rename to src/main/kotlin/roomescape/reservation/web/ReservationController.kt
index 81be3fc1..ccdb85c5 100644
--- a/src/main/java/roomescape/reservation/web/ReservationController.kt
+++ b/src/main/kotlin/roomescape/reservation/web/ReservationController.kt
@@ -8,8 +8,8 @@ import roomescape.auth.web.support.MemberId
 import roomescape.common.dto.response.CommonApiResponse
 import roomescape.common.exception.RoomescapeException
 import roomescape.payment.infrastructure.client.PaymentApproveRequest
-import roomescape.payment.infrastructure.client.TossPaymentClient
 import roomescape.payment.infrastructure.client.PaymentApproveResponse
+import roomescape.payment.infrastructure.client.TossPaymentClient
 import roomescape.payment.web.PaymentCancelRequest
 import roomescape.reservation.business.ReservationService
 import roomescape.reservation.business.ReservationWithPaymentService
diff --git a/src/main/java/roomescape/reservation/web/ReservationRequest.kt b/src/main/kotlin/roomescape/reservation/web/ReservationRequest.kt
similarity index 100%
rename from src/main/java/roomescape/reservation/web/ReservationRequest.kt
rename to src/main/kotlin/roomescape/reservation/web/ReservationRequest.kt
diff --git a/src/main/java/roomescape/reservation/web/ReservationResponse.kt b/src/main/kotlin/roomescape/reservation/web/ReservationResponse.kt
similarity index 100%
rename from src/main/java/roomescape/reservation/web/ReservationResponse.kt
rename to src/main/kotlin/roomescape/reservation/web/ReservationResponse.kt
diff --git a/src/main/java/roomescape/reservation/web/TimeController.kt b/src/main/kotlin/roomescape/reservation/web/TimeController.kt
similarity index 100%
rename from src/main/java/roomescape/reservation/web/TimeController.kt
rename to src/main/kotlin/roomescape/reservation/web/TimeController.kt
diff --git a/src/main/java/roomescape/reservation/web/TimeDTO.kt b/src/main/kotlin/roomescape/reservation/web/TimeDTO.kt
similarity index 100%
rename from src/main/java/roomescape/reservation/web/TimeDTO.kt
rename to src/main/kotlin/roomescape/reservation/web/TimeDTO.kt
diff --git a/src/main/java/roomescape/theme/business/ThemeService.kt b/src/main/kotlin/roomescape/theme/business/ThemeService.kt
similarity index 99%
rename from src/main/java/roomescape/theme/business/ThemeService.kt
rename to src/main/kotlin/roomescape/theme/business/ThemeService.kt
index 82ddf48c..a1b05146 100644
--- a/src/main/java/roomescape/theme/business/ThemeService.kt
+++ b/src/main/kotlin/roomescape/theme/business/ThemeService.kt
@@ -30,7 +30,6 @@ class ThemeService(
     fun findAll(): ThemesResponse = themeRepository.findAll()
             .toResponse()
 
-
     @Transactional(readOnly = true)
     fun findMostReservedThemes(count: Int): ThemesResponse {
         val today = LocalDate.now()
diff --git a/src/main/java/roomescape/theme/docs/ThemeAPI.kt b/src/main/kotlin/roomescape/theme/docs/ThemeAPI.kt
similarity index 100%
rename from src/main/java/roomescape/theme/docs/ThemeAPI.kt
rename to src/main/kotlin/roomescape/theme/docs/ThemeAPI.kt
diff --git a/src/main/java/roomescape/theme/infrastructure/persistence/ThemeEntity.kt b/src/main/kotlin/roomescape/theme/infrastructure/persistence/ThemeEntity.kt
similarity index 100%
rename from src/main/java/roomescape/theme/infrastructure/persistence/ThemeEntity.kt
rename to src/main/kotlin/roomescape/theme/infrastructure/persistence/ThemeEntity.kt
diff --git a/src/main/java/roomescape/theme/infrastructure/persistence/ThemeRepository.kt b/src/main/kotlin/roomescape/theme/infrastructure/persistence/ThemeRepository.kt
similarity index 100%
rename from src/main/java/roomescape/theme/infrastructure/persistence/ThemeRepository.kt
rename to src/main/kotlin/roomescape/theme/infrastructure/persistence/ThemeRepository.kt
diff --git a/src/main/java/roomescape/theme/web/ThemeController.kt b/src/main/kotlin/roomescape/theme/web/ThemeController.kt
similarity index 100%
rename from src/main/java/roomescape/theme/web/ThemeController.kt
rename to src/main/kotlin/roomescape/theme/web/ThemeController.kt
diff --git a/src/main/java/roomescape/theme/web/ThemeDTO.kt b/src/main/kotlin/roomescape/theme/web/ThemeDTO.kt
similarity index 99%
rename from src/main/java/roomescape/theme/web/ThemeDTO.kt
rename to src/main/kotlin/roomescape/theme/web/ThemeDTO.kt
index a2940b6a..5fa35711 100644
--- a/src/main/java/roomescape/theme/web/ThemeDTO.kt
+++ b/src/main/kotlin/roomescape/theme/web/ThemeDTO.kt
@@ -46,7 +46,6 @@ fun ThemeEntity.toResponse(): ThemeResponse = ThemeResponse(
         thumbnail = this.thumbnail
 )
 
-
 @Schema(name = "테마 목록 조회 응답", description = "모든 테마 목록 조회 응답시 사용됩니다.")
 data class ThemesResponse(
         @field:Schema(description = "모든 테마 목록")
diff --git a/src/main/java/roomescape/view/PageController.kt b/src/main/kotlin/roomescape/view/PageController.kt
similarity index 100%
rename from src/main/java/roomescape/view/PageController.kt
rename to src/main/kotlin/roomescape/view/PageController.kt
diff --git a/src/test/java/roomescape/auth/business/AuthServiceTest.kt b/src/test/kotlin/roomescape/auth/business/AuthServiceTest.kt
similarity index 99%
rename from src/test/java/roomescape/auth/business/AuthServiceTest.kt
rename to src/test/kotlin/roomescape/auth/business/AuthServiceTest.kt
index 90fb95cb..5f37c79e 100644
--- a/src/test/java/roomescape/auth/business/AuthServiceTest.kt
+++ b/src/test/kotlin/roomescape/auth/business/AuthServiceTest.kt
@@ -17,7 +17,6 @@ import roomescape.member.infrastructure.persistence.MemberRepository
 import roomescape.util.JwtFixture
 import roomescape.util.MemberFixture
 
-
 class AuthServiceTest : BehaviorSpec({
     val memberRepository: MemberRepository = mockk()
     val memberService: MemberService = MemberService(memberRepository)
diff --git a/src/test/java/roomescape/auth/infrastructure/jwt/JwtHandlerTest.kt b/src/test/kotlin/roomescape/auth/infrastructure/jwt/JwtHandlerTest.kt
similarity index 100%
rename from src/test/java/roomescape/auth/infrastructure/jwt/JwtHandlerTest.kt
rename to src/test/kotlin/roomescape/auth/infrastructure/jwt/JwtHandlerTest.kt
diff --git a/src/test/java/roomescape/auth/web/AuthControllerTest.kt b/src/test/kotlin/roomescape/auth/web/AuthControllerTest.kt
similarity index 100%
rename from src/test/java/roomescape/auth/web/AuthControllerTest.kt
rename to src/test/kotlin/roomescape/auth/web/AuthControllerTest.kt
diff --git a/src/test/java/roomescape/auth/web/support/CookieUtilsTest.kt b/src/test/kotlin/roomescape/auth/web/support/CookieUtilsTest.kt
similarity index 100%
rename from src/test/java/roomescape/auth/web/support/CookieUtilsTest.kt
rename to src/test/kotlin/roomescape/auth/web/support/CookieUtilsTest.kt
diff --git a/src/test/java/roomescape/common/config/JacksonConfigTest.kt b/src/test/kotlin/roomescape/common/config/JacksonConfigTest.kt
similarity index 100%
rename from src/test/java/roomescape/common/config/JacksonConfigTest.kt
rename to src/test/kotlin/roomescape/common/config/JacksonConfigTest.kt
diff --git a/src/test/java/roomescape/member/controller/MemberControllerTest.kt b/src/test/kotlin/roomescape/member/controller/MemberControllerTest.kt
similarity index 100%
rename from src/test/java/roomescape/member/controller/MemberControllerTest.kt
rename to src/test/kotlin/roomescape/member/controller/MemberControllerTest.kt
diff --git a/src/test/java/roomescape/payment/business/PaymentServiceTest.kt b/src/test/kotlin/roomescape/payment/business/PaymentServiceTest.kt
similarity index 100%
rename from src/test/java/roomescape/payment/business/PaymentServiceTest.kt
rename to src/test/kotlin/roomescape/payment/business/PaymentServiceTest.kt
diff --git a/src/test/java/roomescape/payment/infrastructure/client/PaymentCancelResponseDeserializerTest.kt b/src/test/kotlin/roomescape/payment/infrastructure/client/PaymentCancelResponseDeserializerTest.kt
similarity index 100%
rename from src/test/java/roomescape/payment/infrastructure/client/PaymentCancelResponseDeserializerTest.kt
rename to src/test/kotlin/roomescape/payment/infrastructure/client/PaymentCancelResponseDeserializerTest.kt
diff --git a/src/test/java/roomescape/payment/infrastructure/client/SampleTossPaymentConst.kt b/src/test/kotlin/roomescape/payment/infrastructure/client/SampleTossPaymentConst.kt
similarity index 98%
rename from src/test/java/roomescape/payment/infrastructure/client/SampleTossPaymentConst.kt
rename to src/test/kotlin/roomescape/payment/infrastructure/client/SampleTossPaymentConst.kt
index 30f544a9..5f84aa4a 100644
--- a/src/test/java/roomescape/payment/infrastructure/client/SampleTossPaymentConst.kt
+++ b/src/test/kotlin/roomescape/payment/infrastructure/client/SampleTossPaymentConst.kt
@@ -1,6 +1,5 @@
 package roomescape.payment.infrastructure.client
 
-import roomescape.payment.infrastructure.client.PaymentApproveRequest
 import roomescape.payment.web.PaymentCancelRequest
 import kotlin.math.roundToLong
 
diff --git a/src/test/java/roomescape/payment/infrastructure/client/TossPaymentClientTest.kt b/src/test/kotlin/roomescape/payment/infrastructure/client/TossPaymentClientTest.kt
similarity index 100%
rename from src/test/java/roomescape/payment/infrastructure/client/TossPaymentClientTest.kt
rename to src/test/kotlin/roomescape/payment/infrastructure/client/TossPaymentClientTest.kt
diff --git a/src/test/java/roomescape/payment/infrastructure/persistence/CanceledPaymentRepositoryTest.kt b/src/test/kotlin/roomescape/payment/infrastructure/persistence/CanceledPaymentRepositoryTest.kt
similarity index 100%
rename from src/test/java/roomescape/payment/infrastructure/persistence/CanceledPaymentRepositoryTest.kt
rename to src/test/kotlin/roomescape/payment/infrastructure/persistence/CanceledPaymentRepositoryTest.kt
diff --git a/src/test/java/roomescape/payment/infrastructure/persistence/PaymentRepositoryTest.kt b/src/test/kotlin/roomescape/payment/infrastructure/persistence/PaymentRepositoryTest.kt
similarity index 100%
rename from src/test/java/roomescape/payment/infrastructure/persistence/PaymentRepositoryTest.kt
rename to src/test/kotlin/roomescape/payment/infrastructure/persistence/PaymentRepositoryTest.kt
diff --git a/src/test/java/roomescape/reservation/business/ReservationServiceTest.kt b/src/test/kotlin/roomescape/reservation/business/ReservationServiceTest.kt
similarity index 100%
rename from src/test/java/roomescape/reservation/business/ReservationServiceTest.kt
rename to src/test/kotlin/roomescape/reservation/business/ReservationServiceTest.kt
diff --git a/src/test/java/roomescape/reservation/business/ReservationWithPaymentServiceTest.kt b/src/test/kotlin/roomescape/reservation/business/ReservationWithPaymentServiceTest.kt
similarity index 100%
rename from src/test/java/roomescape/reservation/business/ReservationWithPaymentServiceTest.kt
rename to src/test/kotlin/roomescape/reservation/business/ReservationWithPaymentServiceTest.kt
diff --git a/src/test/java/roomescape/reservation/business/TimeServiceTest.kt b/src/test/kotlin/roomescape/reservation/business/TimeServiceTest.kt
similarity index 99%
rename from src/test/java/roomescape/reservation/business/TimeServiceTest.kt
rename to src/test/kotlin/roomescape/reservation/business/TimeServiceTest.kt
index c25f96f7..2e39c9b4 100644
--- a/src/test/java/roomescape/reservation/business/TimeServiceTest.kt
+++ b/src/test/kotlin/roomescape/reservation/business/TimeServiceTest.kt
@@ -73,7 +73,7 @@ class TimeServiceTest : FunSpec({
             val time = TimeFixture.create()
 
             every { timeRepository.findByIdOrNull(id) } returns time
-            
+
             every { reservationRepository.findByTime(time) } returns listOf(mockk())
 
             shouldThrow<RoomescapeException> {
diff --git a/src/test/java/roomescape/reservation/infrastructure/persistence/ReservationRepositoryTest.kt b/src/test/kotlin/roomescape/reservation/infrastructure/persistence/ReservationRepositoryTest.kt
similarity index 100%
rename from src/test/java/roomescape/reservation/infrastructure/persistence/ReservationRepositoryTest.kt
rename to src/test/kotlin/roomescape/reservation/infrastructure/persistence/ReservationRepositoryTest.kt
index e2e9ee82..968a0073 100644
--- a/src/test/java/roomescape/reservation/infrastructure/persistence/ReservationRepositoryTest.kt
+++ b/src/test/kotlin/roomescape/reservation/infrastructure/persistence/ReservationRepositoryTest.kt
@@ -12,8 +12,8 @@ import roomescape.reservation.web.MyReservationRetrieveResponse
 import roomescape.theme.infrastructure.persistence.ThemeEntity
 import roomescape.util.PaymentFixture
 import roomescape.util.ReservationFixture
-import roomescape.util.TimeFixture
 import roomescape.util.ThemeFixture
+import roomescape.util.TimeFixture
 
 @DataJpaTest
 class ReservationRepositoryTest(
diff --git a/src/test/java/roomescape/reservation/infrastructure/persistence/ReservationSearchSpecificationTest.kt b/src/test/kotlin/roomescape/reservation/infrastructure/persistence/ReservationSearchSpecificationTest.kt
similarity index 100%
rename from src/test/java/roomescape/reservation/infrastructure/persistence/ReservationSearchSpecificationTest.kt
rename to src/test/kotlin/roomescape/reservation/infrastructure/persistence/ReservationSearchSpecificationTest.kt
index 7d97ca3e..6d764f42 100644
--- a/src/test/java/roomescape/reservation/infrastructure/persistence/ReservationSearchSpecificationTest.kt
+++ b/src/test/kotlin/roomescape/reservation/infrastructure/persistence/ReservationSearchSpecificationTest.kt
@@ -10,8 +10,8 @@ import roomescape.member.infrastructure.persistence.MemberEntity
 import roomescape.theme.infrastructure.persistence.ThemeEntity
 import roomescape.util.MemberFixture
 import roomescape.util.ReservationFixture
-import roomescape.util.TimeFixture
 import roomescape.util.ThemeFixture
+import roomescape.util.TimeFixture
 import java.time.LocalDate
 
 @DataJpaTest
diff --git a/src/test/java/roomescape/reservation/infrastructure/persistence/TimeRepositoryTest.kt b/src/test/kotlin/roomescape/reservation/infrastructure/persistence/TimeRepositoryTest.kt
similarity index 100%
rename from src/test/java/roomescape/reservation/infrastructure/persistence/TimeRepositoryTest.kt
rename to src/test/kotlin/roomescape/reservation/infrastructure/persistence/TimeRepositoryTest.kt
diff --git a/src/test/java/roomescape/reservation/web/ReservationControllerTest.kt b/src/test/kotlin/roomescape/reservation/web/ReservationControllerTest.kt
similarity index 100%
rename from src/test/java/roomescape/reservation/web/ReservationControllerTest.kt
rename to src/test/kotlin/roomescape/reservation/web/ReservationControllerTest.kt
diff --git a/src/test/java/roomescape/reservation/web/TimeControllerTest.kt b/src/test/kotlin/roomescape/reservation/web/TimeControllerTest.kt
similarity index 100%
rename from src/test/java/roomescape/reservation/web/TimeControllerTest.kt
rename to src/test/kotlin/roomescape/reservation/web/TimeControllerTest.kt
index 57f6cfbc..3e9b9968 100644
--- a/src/test/java/roomescape/reservation/web/TimeControllerTest.kt
+++ b/src/test/kotlin/roomescape/reservation/web/TimeControllerTest.kt
@@ -18,9 +18,9 @@ import roomescape.reservation.infrastructure.persistence.ReservationRepository
 import roomescape.reservation.infrastructure.persistence.TimeEntity
 import roomescape.reservation.infrastructure.persistence.TimeRepository
 import roomescape.util.ReservationFixture
-import roomescape.util.TimeFixture
 import roomescape.util.RoomescapeApiTest
 import roomescape.util.ThemeFixture
+import roomescape.util.TimeFixture
 import java.time.LocalDate
 import java.time.LocalTime
 
diff --git a/src/test/java/roomescape/theme/business/ThemeServiceTest.kt b/src/test/kotlin/roomescape/theme/business/ThemeServiceTest.kt
similarity index 100%
rename from src/test/java/roomescape/theme/business/ThemeServiceTest.kt
rename to src/test/kotlin/roomescape/theme/business/ThemeServiceTest.kt
diff --git a/src/test/java/roomescape/theme/infrastructure/persistence/ThemeRepositoryTest.kt b/src/test/kotlin/roomescape/theme/infrastructure/persistence/ThemeRepositoryTest.kt
similarity index 100%
rename from src/test/java/roomescape/theme/infrastructure/persistence/ThemeRepositoryTest.kt
rename to src/test/kotlin/roomescape/theme/infrastructure/persistence/ThemeRepositoryTest.kt
diff --git a/src/test/java/roomescape/theme/util/TestThemeCreateUtil.kt b/src/test/kotlin/roomescape/theme/util/TestThemeCreateUtil.kt
similarity index 100%
rename from src/test/java/roomescape/theme/util/TestThemeCreateUtil.kt
rename to src/test/kotlin/roomescape/theme/util/TestThemeCreateUtil.kt
index 7966162f..0dacd49b 100644
--- a/src/test/java/roomescape/theme/util/TestThemeCreateUtil.kt
+++ b/src/test/kotlin/roomescape/theme/util/TestThemeCreateUtil.kt
@@ -7,8 +7,8 @@ import roomescape.reservation.infrastructure.persistence.TimeEntity
 import roomescape.theme.infrastructure.persistence.ThemeEntity
 import roomescape.util.MemberFixture
 import roomescape.util.ReservationFixture
-import roomescape.util.TimeFixture
 import roomescape.util.ThemeFixture
+import roomescape.util.TimeFixture
 import java.time.LocalDate
 import java.time.LocalTime
 
diff --git a/src/test/java/roomescape/theme/web/MostReservedThemeAPITest.kt b/src/test/kotlin/roomescape/theme/web/MostReservedThemeApiTest.kt
similarity index 71%
rename from src/test/java/roomescape/theme/web/MostReservedThemeAPITest.kt
rename to src/test/kotlin/roomescape/theme/web/MostReservedThemeApiTest.kt
index 73b62fdf..5ebf0851 100644
--- a/src/test/java/roomescape/theme/web/MostReservedThemeAPITest.kt
+++ b/src/test/kotlin/roomescape/theme/web/MostReservedThemeApiTest.kt
@@ -9,22 +9,15 @@ import org.hamcrest.Matchers.equalTo
 import org.springframework.boot.test.context.SpringBootTest
 import org.springframework.boot.test.web.server.LocalServerPort
 import org.springframework.transaction.support.TransactionTemplate
-import roomescape.theme.business.ThemeService
 import roomescape.theme.util.TestThemeCreateUtil
 import roomescape.util.CleanerMode
 import roomescape.util.DatabaseCleanerExtension
 import java.time.LocalDate
 import kotlin.random.Random
 
-/**
- * GET /themes/most-reserved-last-week API 테스트
- * 상세 테스트는 Repository 테스트에서 진행
- * 날짜 범위, 예약 수만 검증
- */
 @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
-class MostReservedThemeAPITest(
+class MostReservedThemeApiTest(
         @LocalServerPort val port: Int,
-        val themeService: ThemeService,
         val transactionTemplate: TransactionTemplate,
         val entityManager: EntityManager,
 ) : FunSpec({
@@ -53,59 +46,55 @@ class MostReservedThemeAPITest(
             }
         }
 
-        context("가장 많이 예약된 테마를 조회할 때,  ") {
+        context("지난 주 가장 많이 예약된 테마 API") {
             val endpoint = "/themes/most-reserved-last-week"
-            test("갯수를 입력하지 않으면 10개를 반환한다.") {
+
+            test("count 파라미터가 없으면 10개를 반환한다") {
                 Given {
                     port(port)
                 } When {
                     get(endpoint)
                 } Then {
-                    log().all()
                     statusCode(200)
                     body("data.themes.size()", equalTo(10))
                 }
             }
 
-            test("입력된 갯수가 조회된 갯수보다 크면 조회된 갯수만큼 반환한다.") {
+            test("조회된 테마가 count보다 적으면 조회된 만큼 반환한다") {
                 val count = 15
                 Given {
                     port(port)
-                } When {
                     param("count", count)
-                    get("/themes/most-reserved-last-week")
+                } When {
+                    get(endpoint)
                 } Then {
-                    log().all()
                     statusCode(200)
                     body("data.themes.size()", equalTo(10))
                 }
             }
 
-            test("입력된 갯수가 조회된 갯수보다 작으면 입력된 갯수만큼 반환한다.") {
+            test("조회된 테마가 count보다 많으면 count만큼 반환한다") {
                 val count = 5
                 Given {
                     port(port)
-                } When {
                     param("count", count)
-                    get("/themes/most-reserved-last-week")
+                } When {
+                    get(endpoint)
                 } Then {
-                    log().all()
                     statusCode(200)
                     body("data.themes.size()", equalTo(count))
                 }
             }
 
-            test("7일 전 부터 1일 전 까지 예약된 테마를 대상으로 한다.") {
-                // 현재 저장된 데이터는 지난 7일간 예약된 테마 10개와 8일 전 예약된 테마 1개
-                // 8일 전 예약된 테마는 제외되어야 하므로, 10개가 조회되어야 한다.
+            test("지난 7일 동안의 예약만 집계한다") {
+                // 8일 전에 예약된 테마는 집계에서 제외되어야 한다.
                 val count = 11
                 Given {
                     port(port)
-                } When {
                     param("count", count)
-                    get("/themes/most-reserved-last-week")
+                } When {
+                    get(endpoint)
                 } Then {
-                    log().all()
                     statusCode(200)
                     body("data.themes.size()", equalTo(10))
                 }
diff --git a/src/test/java/roomescape/theme/web/ThemeControllerTest.kt b/src/test/kotlin/roomescape/theme/web/ThemeControllerTest.kt
similarity index 100%
rename from src/test/java/roomescape/theme/web/ThemeControllerTest.kt
rename to src/test/kotlin/roomescape/theme/web/ThemeControllerTest.kt
diff --git a/src/test/java/roomescape/util/DatabaseCleaner.kt b/src/test/kotlin/roomescape/util/DatabaseCleaner.kt
similarity index 100%
rename from src/test/java/roomescape/util/DatabaseCleaner.kt
rename to src/test/kotlin/roomescape/util/DatabaseCleaner.kt
diff --git a/src/test/java/roomescape/util/Fixtures.kt b/src/test/kotlin/roomescape/util/Fixtures.kt
similarity index 100%
rename from src/test/java/roomescape/util/Fixtures.kt
rename to src/test/kotlin/roomescape/util/Fixtures.kt
index 02f7a074..21316345 100644
--- a/src/test/java/roomescape/util/Fixtures.kt
+++ b/src/test/kotlin/roomescape/util/Fixtures.kt
@@ -4,10 +4,10 @@ import roomescape.auth.infrastructure.jwt.JwtHandler
 import roomescape.auth.web.LoginRequest
 import roomescape.member.infrastructure.persistence.MemberEntity
 import roomescape.member.infrastructure.persistence.Role
-import roomescape.payment.infrastructure.persistence.CanceledPaymentEntity
-import roomescape.payment.infrastructure.persistence.PaymentEntity
 import roomescape.payment.infrastructure.client.PaymentApproveRequest
 import roomescape.payment.infrastructure.client.PaymentApproveResponse
+import roomescape.payment.infrastructure.persistence.CanceledPaymentEntity
+import roomescape.payment.infrastructure.persistence.PaymentEntity
 import roomescape.payment.web.PaymentCancelRequest
 import roomescape.payment.web.PaymentCancelResponse
 import roomescape.reservation.infrastructure.persistence.ReservationEntity
diff --git a/src/test/java/roomescape/util/KotestConfig.kt b/src/test/kotlin/roomescape/util/KotestConfig.kt
similarity index 100%
rename from src/test/java/roomescape/util/KotestConfig.kt
rename to src/test/kotlin/roomescape/util/KotestConfig.kt
diff --git a/src/test/java/roomescape/util/RoomescapeApiTest.kt b/src/test/kotlin/roomescape/util/RoomescapeApiTest.kt
similarity index 100%
rename from src/test/java/roomescape/util/RoomescapeApiTest.kt
rename to src/test/kotlin/roomescape/util/RoomescapeApiTest.kt
diff --git a/src/test/java/roomescape/view/PageControllerTest.kt b/src/test/kotlin/roomescape/view/PageControllerTest.kt
similarity index 100%
rename from src/test/java/roomescape/view/PageControllerTest.kt
rename to src/test/kotlin/roomescape/view/PageControllerTest.kt