diff --git a/src/main/java/com/magamochi/catalog/model/repository/MangaRepository.java b/src/main/java/com/magamochi/catalog/model/repository/MangaRepository.java
index 1d43a30..039479c 100644
--- a/src/main/java/com/magamochi/catalog/model/repository/MangaRepository.java
+++ b/src/main/java/com/magamochi/catalog/model/repository/MangaRepository.java
@@ -9,7 +9,7 @@ import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
 
 public interface MangaRepository
     extends JpaRepository<Manga, Long>, JpaSpecificationExecutor<Manga> {
-  Optional<Manga> findByTitleIgnoreCase(String title);
+  List<Manga> findAllByTitleIgnoreCase(String title);
 
   List<Manga> findByFollowTrue();
 
diff --git a/src/main/java/com/magamochi/catalog/service/MangaResolutionService.java b/src/main/java/com/magamochi/catalog/service/MangaResolutionService.java
index ee3e487..a38740b 100644
--- a/src/main/java/com/magamochi/catalog/service/MangaResolutionService.java
+++ b/src/main/java/com/magamochi/catalog/service/MangaResolutionService.java
@@ -26,9 +26,14 @@ public class MangaResolutionService {
   private final MangaRepository mangaRepository;
 
   public Manga findOrCreateManga(String searchTitle) {
-    var existingManga = mangaRepository.findByTitleIgnoreCase(searchTitle);
-    if (existingManga.isPresent()) {
-      return existingManga.get();
+    var existingMangas = mangaRepository.findAllByTitleIgnoreCase(searchTitle);
+    if (existingMangas.size() == 1) {
+      return existingMangas.get(0);
+    }
+    if (existingMangas.size() > 1) {
+      log.warn(
+          "Multiple mangas with title '{}', falling through to external ID resolution",
+          searchTitle);
     }
 
     var aniListResult = searchMangaOnAniList(searchTitle);
@@ -130,9 +135,16 @@ public class MangaResolutionService {
     }
 
     if (nonNull(canonicalTitle)) {
-      var existingByTitle = mangaRepository.findByTitleIgnoreCase(canonicalTitle);
-      if (existingByTitle.isPresent()) {
-        return mergeExternalIds(existingByTitle.get(), canonicalTitle, aniListId, malId);
+      var existingByTitle = mangaRepository.findAllByTitleIgnoreCase(canonicalTitle);
+      if (existingByTitle.size() == 1) {
+        return mergeExternalIds(existingByTitle.get(0), canonicalTitle, aniListId, malId);
+      }
+      if (existingByTitle.size() > 1) {
+        log.warn(
+            "Multiple mangas with canonical title '{}', merging into first (ID: {})",
+            canonicalTitle,
+            existingByTitle.get(0).getId());
+        return mergeExternalIds(existingByTitle.get(0), canonicalTitle, aniListId, malId);
       }
     }
 
@@ -148,7 +160,8 @@ public class MangaResolutionService {
       try {
         mangaUpdateProducer.sendMangaUpdateCommand(new MangaUpdateCommand(manga.getId()));
       } catch (Exception e) {
-        log.error("Failed to send manga update command for manga '{}' (ID: {})", title, manga.getId(), e);
+        log.error(
+            "Failed to send manga update command for manga '{}' (ID: {})", title, manga.getId(), e);
       }
 
       return manga;
@@ -172,9 +185,16 @@ public class MangaResolutionService {
         }
       }
       if (nonNull(title)) {
-        var existing = mangaRepository.findByTitleIgnoreCase(title);
-        if (existing.isPresent()) {
-          return mergeExternalIds(existing.get(), title, aniListId, malId);
+        var existingByTitle = mangaRepository.findAllByTitleIgnoreCase(title);
+        if (existingByTitle.size() == 1) {
+          return mergeExternalIds(existingByTitle.get(0), title, aniListId, malId);
+        }
+        if (existingByTitle.size() > 1) {
+          log.warn(
+              "Multiple mangas with title '{}', merging into first (ID: {})",
+              title,
+              existingByTitle.get(0).getId());
+          return mergeExternalIds(existingByTitle.get(0), title, aniListId, malId);
         }
       }
 
@@ -182,7 +202,8 @@ public class MangaResolutionService {
     }
   }
 
-  private Manga mergeExternalIds(Manga existing, String canonicalTitle, Long aniListId, Long malId) {
+  private Manga mergeExternalIds(
+      Manga existing, String canonicalTitle, Long aniListId, Long malId) {
     boolean updated = false;
 
     if (isNull(existing.getAniListId()) && nonNull(aniListId)) {