diff --git a/include/tanabata.h b/include/tanabata.h
index f8fca1f..64c98b7 100644
--- a/include/tanabata.h
+++ b/include/tanabata.h
@@ -40,7 +40,7 @@ int tanabata_dump(Tanabata *tanabata, const char *path);
 // ==================== SASA SECTION ==================== //
 
 // Add sasa
-int tanabata_sasa_add(Tanabata *tanabata, const char *path);
+uint64_t tanabata_sasa_add(Tanabata *tanabata, const char *path);
 
 // Remove sasa by ID
 int tanabata_sasa_rem(Tanabata *tanabata, uint64_t sasa_id);
diff --git a/tanabata/core/core_func.h b/tanabata/core/core_func.h
index 7b6ca17..c4d8e7c 100644
--- a/tanabata/core/core_func.h
+++ b/tanabata/core/core_func.h
@@ -35,7 +35,7 @@ int sasahyou_open(Sasahyou *sasahyou, const char *path);
 int sasahyou_dump(Sasahyou *sasahyou, const char *path);
 
 // Add sasa to sasahyou
-int sasa_add(Sasahyou *sasahyou, const char *path);
+uint64_t sasa_add(Sasahyou *sasahyou, const char *path);
 
 // Remove sasa from sasahyou
 int sasa_rem(Sasahyou *sasahyou, uint64_t sasa_id);
diff --git a/tanabata/core/sasahyou.c b/tanabata/core/sasahyou.c
index 6ec7ffa..cd80ef1 100644
--- a/tanabata/core/sasahyou.c
+++ b/tanabata/core/sasahyou.c
@@ -144,9 +144,9 @@ int sasahyou_dump(Sasahyou *sasahyou, const char *path) {
     return sasahyou_save(sasahyou);
 }
 
-int sasa_add(Sasahyou *sasahyou, const char *path) {
+uint64_t sasa_add(Sasahyou *sasahyou, const char *path) {
     if (path == NULL || sasahyou->size == -1 && sasahyou->hole_cnt == 0) {
-        return 1;
+        return HOLE_ID;
     }
     Sasa newbie;
     newbie.created_ts = time(NULL);
@@ -165,7 +165,7 @@ int sasa_add(Sasahyou *sasahyou, const char *path) {
         sasahyou->database[newbie.id] = newbie;
     }
     sasahyou->modified_ts = newbie.created_ts;
-    return 0;
+    return newbie.id;
 }
 
 int sasa_rem(Sasahyou *sasahyou, uint64_t sasa_id) {
diff --git a/tanabata/lib/sasa.c b/tanabata/lib/sasa.c
index 750e2a6..fc83553 100644
--- a/tanabata/lib/sasa.c
+++ b/tanabata/lib/sasa.c
@@ -1,7 +1,7 @@
 #include "../core/core_func.h"
 #include "../../include/tanabata.h"
 
-int tanabata_sasa_add(Tanabata *tanabata, const char *path) {
+uint64_t tanabata_sasa_add(Tanabata *tanabata, const char *path) {
     return sasa_add(&tanabata->sasahyou, path);
 }