diff --git a/src/main/java/cactusServer/entities/Character.java b/src/main/java/cactusServer/entities/Character.java
index 40dfe65..428842c 100644
--- a/src/main/java/cactusServer/entities/Character.java
+++ b/src/main/java/cactusServer/entities/Character.java
@@ -6,6 +6,7 @@
 import java.util.List;
 import java.util.Map;
 
+import cactusServer.utils.RandomStringGenerator;
 import framework.model3D.Position3D;
 import net.arnx.jsonic.JSONHint;
 
@@ -85,7 +86,7 @@
 	public Map<String, Item> createItem(String name, int amount) {
 		Item item = new Item(name, amount);
 		if (!hasItem(item)) {
-			String id = new RandomStringGenerator().createUniqueString(UNIQUE_ID_LENGTH, RandomStringGenerator.ALPHA_NUMERIC, itemMap.keySet());
+			String id = RandomStringGenerator.generateUniqueString(UNIQUE_ID_LENGTH, RandomStringGenerator.ALPHA_NUMERIC, itemMap.keySet());
 			itemMap.put(id, item);
 			return new HashMap<String, Item>() {
 				{put(id, item);}
diff --git a/src/main/java/cactusServer/entities/Instance.java b/src/main/java/cactusServer/entities/Instance.java
index 4586393..7e2a6ed 100644
--- a/src/main/java/cactusServer/entities/Instance.java
+++ b/src/main/java/cactusServer/entities/Instance.java
@@ -10,6 +10,7 @@
 
 import cactusServer.entities.Area.Allowed;
 import cactusServer.entities.Object;
+import cactusServer.utils.RandomStringGenerator;
 import cactusServer.entities.Character;
 import framework.model3D.Position3D;
 import framework.physics.AngularVelocity3D;
@@ -100,7 +101,7 @@
 	}
 
 	public Map<String, Area> createArea(String areaId, String name, Plain[] regions, HashSet<Allowed> permissions) {
-		String id = new RandomStringGenerator().createUniqueString(UNIQUE_ID_LENGTH, RandomStringGenerator.ALPHA_NUMERIC, areaMap.keySet());
+		String id = RandomStringGenerator.generateUniqueString(UNIQUE_ID_LENGTH, RandomStringGenerator.ALPHA_NUMERIC, areaMap.keySet());
 		Area area = new Area(name, regions, permissions);
 		areaMap.put(id, area);
 		return new HashMap<String, Area>() {
@@ -109,7 +110,7 @@
 	}
 	
 	public Map<String, Object> createObject(String objId, Position3D position, Velocity3D velocity, AngularVelocity3D angularVelocity, Object.Attribute attribute) {
-		String id = new RandomStringGenerator().createUniqueString(UNIQUE_ID_LENGTH, RandomStringGenerator.ALPHA_NUMERIC, objMap.keySet());
+		String id = RandomStringGenerator.generateUniqueString(UNIQUE_ID_LENGTH, RandomStringGenerator.ALPHA_NUMERIC, objMap.keySet());
 		Object object = new Object(position, velocity, angularVelocity, attribute);
 		objMap.put(id, object);
 		return new HashMap<String, Object>() {
@@ -127,7 +128,7 @@
 //	}
 	
 	public Map<String, Character> createCharacter(Character character) {
-		String id = new RandomStringGenerator().createUniqueString(UNIQUE_ID_LENGTH, RandomStringGenerator.ALPHA_NUMERIC, characterMap.keySet());
+		String id = RandomStringGenerator.generateUniqueString(UNIQUE_ID_LENGTH, RandomStringGenerator.ALPHA_NUMERIC, characterMap.keySet());
 		characterMap.put(id, character);
 		return new HashMap<String, Character>() {
 			{put(id, character);}
diff --git a/src/main/java/cactusServer/models/Instances.java b/src/main/java/cactusServer/models/Instances.java
index 48e2bcc..58a82eb 100644
--- a/src/main/java/cactusServer/models/Instances.java
+++ b/src/main/java/cactusServer/models/Instances.java
@@ -6,7 +6,7 @@
 import org.apache.commons.lang3.RandomStringUtils;
 
 import cactusServer.entities.Instance;
-import cactusServer.entities.RandomStringGenerator;
+import cactusServer.utils.RandomStringGenerator;
 import net.arnx.jsonic.JSONHint;
 
 /**
@@ -43,7 +43,7 @@
 	 * @return �V�����쐬���ꂽID��Instance��Map
 	 */
 	public Map<String, Instance> createInstance(Instance instance) {
-		String id = new RandomStringGenerator().createUniqueString(UNIQUE_ID_LENGTH, RandomStringGenerator.ALPHA_NUMERIC, instanceMap.keySet());
+		String id = RandomStringGenerator.generateUniqueString(UNIQUE_ID_LENGTH, RandomStringGenerator.ALPHA_NUMERIC, instanceMap.keySet());
 		instanceMap.put(id, instance);
 		return new HashMap<String, Instance>() {
 			{put(id, instance);}
diff --git a/src/main/java/cactusServer/utils/RandomStringGenerator.java b/src/main/java/cactusServer/utils/RandomStringGenerator.java
index 522e32c..d53dc34 100644
--- a/src/main/java/cactusServer/utils/RandomStringGenerator.java
+++ b/src/main/java/cactusServer/utils/RandomStringGenerator.java
@@ -19,7 +19,7 @@
 		return set.contains(str);
 	}
 
-	static public String createUniqueString(int num, String seed, Set<String> set) {
+	static public String generateUniqueString(int num, String seed, Set<String> set) {
 		String str;
 		do {
 			str = generateRandomString(num, seed);