diff --git a/src/main/kotlin/com/toyProject7/karrot/manner/controller/MannerController.kt b/src/main/kotlin/com/toyProject7/karrot/manner/controller/MannerController.kt
index 225c1e9..3af6fd2 100644
--- a/src/main/kotlin/com/toyProject7/karrot/manner/controller/MannerController.kt
+++ b/src/main/kotlin/com/toyProject7/karrot/manner/controller/MannerController.kt
@@ -5,7 +5,6 @@ import org.springframework.http.ResponseEntity
 import org.springframework.web.bind.annotation.PathVariable
 import org.springframework.web.bind.annotation.PutMapping
 import org.springframework.web.bind.annotation.RestController
-import java.net.URLDecoder
 
 @RestController
 class MannerController(
@@ -16,10 +15,7 @@ class MannerController(
         @PathVariable nickname: String,
         @PathVariable mannerType: MannerType,
     ): ResponseEntity<String> {
-        // Decode the nickname
-        val decodedNickname = URLDecoder.decode(nickname, "UTF-8")
-
-        mannerService.increaseMannerCount(decodedNickname, mannerType)
+        mannerService.increaseMannerCount(nickname, mannerType)
         return ResponseEntity.noContent().build()
     }
 }
diff --git a/src/main/kotlin/com/toyProject7/karrot/profile/ProfileException.kt b/src/main/kotlin/com/toyProject7/karrot/profile/ProfileException.kt
index c90a8de..03aa70a 100644
--- a/src/main/kotlin/com/toyProject7/karrot/profile/ProfileException.kt
+++ b/src/main/kotlin/com/toyProject7/karrot/profile/ProfileException.kt
@@ -16,3 +16,9 @@ class ProfileNotFoundException : ProfileException(
     httpStatusCode = HttpStatus.NOT_FOUND,
     msg = "Profile not found",
 )
+
+class ProfileEditNicknameConflictException : ProfileException(
+    errorCode = 0,
+    httpStatusCode = HttpStatus.CONFLICT,
+    msg = "Nickname conflict",
+)
diff --git a/src/main/kotlin/com/toyProject7/karrot/profile/controller/ProfileController.kt b/src/main/kotlin/com/toyProject7/karrot/profile/controller/ProfileController.kt
index 87f90c6..4403a10 100644
--- a/src/main/kotlin/com/toyProject7/karrot/profile/controller/ProfileController.kt
+++ b/src/main/kotlin/com/toyProject7/karrot/profile/controller/ProfileController.kt
@@ -13,7 +13,6 @@ import org.springframework.web.bind.annotation.PutMapping
 import org.springframework.web.bind.annotation.RequestBody
 import org.springframework.web.bind.annotation.RequestParam
 import org.springframework.web.bind.annotation.RestController
-import java.net.URLDecoder
 
 @RestController
 class ProfileController(
@@ -38,10 +37,7 @@ class ProfileController(
     fun getProfile(
         @PathVariable nickname: String,
     ): ResponseEntity<ProfileResponse> {
-        // Decode nickname
-        val decodedNickname = URLDecoder.decode(nickname, "UTF-8")
-
-        val profile = profileService.getProfile(decodedNickname)
+        val profile = profileService.getProfile(nickname)
         return ResponseEntity.ok(profile)
     }
 
@@ -50,10 +46,7 @@ class ProfileController(
         @PathVariable nickname: String,
         @RequestParam articleId: Long,
     ): ResponseEntity<List<Item>> {
-        // Decode nickname
-        val decodedNickname = URLDecoder.decode(nickname, "UTF-8")
-
-        val itemList: List<Item> = profileService.getProfileSells(decodedNickname, articleId)
+        val itemList: List<Item> = profileService.getProfileSells(nickname, articleId)
         return ResponseEntity.ok(itemList)
     }
 
@@ -70,10 +63,7 @@ class ProfileController(
     fun getManners(
         @PathVariable nickname: String,
     ): ResponseEntity<MannersResponse> {
-        // Decode nickname
-        val decodedNickname = URLDecoder.decode(nickname, "UTF-8")
-
-        val manners = profileService.getManner(decodedNickname)
+        val manners = profileService.getManner(nickname)
         return ResponseEntity.ok(manners)
     }
 
@@ -82,10 +72,7 @@ class ProfileController(
         @PathVariable nickname: String,
         @RequestParam("reviewId") reviewId: Long,
     ): ResponseEntity<ReviewsResponse> {
-        // Decode nickname
-        val decodedNickname = URLDecoder.decode(nickname, "UTF-8")
-
-        val reviews = profileService.getPreviousReviews(decodedNickname, reviewId)
+        val reviews = profileService.getPreviousReviews(nickname, reviewId)
         return ResponseEntity.ok(reviews)
     }
 }
diff --git a/src/main/kotlin/com/toyProject7/karrot/profile/service/ProfileService.kt b/src/main/kotlin/com/toyProject7/karrot/profile/service/ProfileService.kt
index 657c8b8..c7b12e2 100644
--- a/src/main/kotlin/com/toyProject7/karrot/profile/service/ProfileService.kt
+++ b/src/main/kotlin/com/toyProject7/karrot/profile/service/ProfileService.kt
@@ -6,17 +6,16 @@ import com.toyProject7.karrot.article.service.ArticleService
 import com.toyProject7.karrot.image.persistence.ImageUrlEntity
 import com.toyProject7.karrot.image.service.ImageService
 import com.toyProject7.karrot.manner.controller.Manner
+import com.toyProject7.karrot.profile.ProfileEditNicknameConflictException
 import com.toyProject7.karrot.profile.ProfileNotFoundException
 import com.toyProject7.karrot.profile.controller.EditProfileRequest
 import com.toyProject7.karrot.profile.controller.Profile
 import com.toyProject7.karrot.profile.persistence.ProfileEntity
 import com.toyProject7.karrot.profile.persistence.ProfileRepository
 import com.toyProject7.karrot.review.controller.Review
-import com.toyProject7.karrot.review.service.ReviewService
 import com.toyProject7.karrot.user.controller.User
 import com.toyProject7.karrot.user.persistence.UserEntity
 import com.toyProject7.karrot.user.service.UserService
-import org.springframework.context.annotation.Lazy
 import org.springframework.stereotype.Service
 import org.springframework.transaction.annotation.Transactional
 import java.time.Instant
@@ -28,7 +27,6 @@ class ProfileService(
     private val userService: UserService,
     private val articleService: ArticleService,
     private val imageService: ImageService,
-    @Lazy private val reviewService: ReviewService,
 ) {
     @Transactional
     fun getMyProfile(user: User): Profile {
@@ -71,6 +69,10 @@ class ProfileService(
         user: User,
         request: EditProfileRequest,
     ): Profile {
+        if (userService.existUserEntityByNickname(request.nickname)) {
+            throw ProfileEditNicknameConflictException()
+        }
+
         val userEntity = userService.getUserEntityById(user.id)
         val profileEntity = profileRepository.findByUserId(user.id) ?: throw ProfileNotFoundException()
         val itemCount = getItemCount(user.id)
diff --git a/src/main/kotlin/com/toyProject7/karrot/user/service/UserService.kt b/src/main/kotlin/com/toyProject7/karrot/user/service/UserService.kt
index 1510012..e3ca5a6 100644
--- a/src/main/kotlin/com/toyProject7/karrot/user/service/UserService.kt
+++ b/src/main/kotlin/com/toyProject7/karrot/user/service/UserService.kt
@@ -179,4 +179,9 @@ class UserService(
     fun getUserEntityByNickname(nickname: String): UserEntity {
         return userRepository.findByNickname(nickname) ?: throw UserNotFoundException()
     }
+
+    @Transactional
+    fun existUserEntityByNickname(nickname: String): Boolean {
+        return userRepository.existsByNickname(nickname)
+    }
 }