diff --git a/src/main/java/cactusServer/entities/Area.java b/src/main/java/cactusServer/entities/Area.java
index 90cfee8..20496b4 100644
--- a/src/main/java/cactusServer/entities/Area.java
+++ b/src/main/java/cactusServer/entities/Area.java
@@ -44,14 +44,12 @@
 
 	public boolean isSurroundingPosition(Position3D position) {
 		for (Plain plain : region) {
-			// ������ Plain��a,b,c,d �� Character��x,y,z ��p����, �L�����N�^�[�����ʂɂ��邩�ǂ����̔�����s��
-
-			// double equation = (plain.getA() * position.getX()) + (plain.getB() *
-			// position.getY())
-			// + (plain.getC() * position.getZ()) + plain.getD();
-			// if (equation > 0) {
-			// return false;
-			// }
+			// ������ Plain��a,b,c,d �� Character��x,y,z ��p����, �L�����N�^�[�����ʂ̗��ɂ��邩�ǂ����̔�����s��
+			double equation = (plain.getA() * position.getX()) + (plain.getB() * position.getY())
+					+ (plain.getC() * position.getZ()) + plain.getD();
+			if (equation > 0) {
+				return false;
+			}
 		}
 		return true;
 	}
diff --git a/src/main/java/cactusServer/entities/Character.java b/src/main/java/cactusServer/entities/Character.java
index 7b67348..08c2516 100644
--- a/src/main/java/cactusServer/entities/Character.java
+++ b/src/main/java/cactusServer/entities/Character.java
@@ -145,21 +145,27 @@
 		for (String areaId : instance.getAreaIdSet()) {
 			Area area = instance.getArea(areaId);
 			if (area.isSurroundingPosition(position)) {
-				int subStringStartIndex = areaURI.length() - Area.UNIQUE_ID_LENGTH;
+				int subStringEndIndex = areaURI.length() - Area.UNIQUE_ID_LENGTH;
 				StringBuilder newAreaURI = new StringBuilder();
-				return newAreaURI.append(areaURI.substring(0, subStringStartIndex)).append(areaId).toString();
+				return newAreaURI.append(areaURI.substring(0, subStringEndIndex)).append(areaId).toString();
 			}
 		}
-		throw new IllegalStateException("Character is in the unknown area.");
+		return "";
 	}
-	
-	public void update(Position3D position, Angle angle, String model) {
+
+	public void update(Position3D position, Angle angle, String model, String areaURI) {
 		setPosition(position);
 		setAngle(angle);
-		setModel(model);
-		updateAreaURI();
+		if (model != null) {
+			setModel(model);
+		}
+		if (areaURI != null) {
+			setAreaURI(areaURI);
+		} else {
+			updateAreaURI();
+		}
 	}
-	
+
 	private void updateAreaURI() {
 		String[] areaURISplit = areaURI.split("/"); // �c�c/instances/{instanceId}/areas/{areaId}
 		int splitSize = areaURISplit.length;
diff --git a/src/main/java/cactusServer/entities/Instance.java b/src/main/java/cactusServer/entities/Instance.java
index b2df2ab..e8860ad 100644
--- a/src/main/java/cactusServer/entities/Instance.java
+++ b/src/main/java/cactusServer/entities/Instance.java
@@ -20,7 +20,7 @@
 /**
  * �C���X�^���X
  * 
- * @author ryo isitani
+ * @author r-isitani
  *
  */
 public class Instance extends Entity {
@@ -143,7 +143,7 @@
 
 	public Character updateCharacter(String characterId, Position3D position, Angle angle, String model) {
 		Character character = characterMap.get(characterId);
-		character.update(position, angle, model);
+		character.update(position, angle, model, null); // areaURI(��4����)�̍X�V�͌Ăяo����Ŏ����ōs����
 		return character;
 	}
 
diff --git a/src/main/java/cactusServer/entities/Player.java b/src/main/java/cactusServer/entities/Player.java
index eafe72f..4d1ce8e 100644
--- a/src/main/java/cactusServer/entities/Player.java
+++ b/src/main/java/cactusServer/entities/Player.java
@@ -102,8 +102,9 @@
 	public void setAnimationClassToStart(EmoteState.EmoteType animationClassToStart) {
 		setEmoteState(new EmoteState(animationClassToStart));
 	}
-	
-	public Player update(String characterURI, Position3D position, Angle angle, CameraState cameraState, EmoteState.EmoteType animationClassToStart) {
+
+	public Player update(String characterURI, Position3D position, Angle angle, CameraState cameraState,
+			EmoteState.EmoteType animationClassToStart) {
 		setCharacterURI(characterURI);
 		setPosition(position);
 		setAngle(angle);
@@ -131,26 +132,24 @@
 		for (String areaId : instance.getAreaIdSet()) {
 			Area area = instance.getArea(areaId);
 			if (area.isSurroundingPosition(position)) {
-				int subStringStartIndex = areaURI.length() - Area.UNIQUE_ID_LENGTH;
+				int subStringEndIndex = areaURI.length() - Area.UNIQUE_ID_LENGTH;
 				StringBuilder newAreaURI = new StringBuilder();
-				return newAreaURI.append(areaURI.substring(0, subStringStartIndex)).append(areaId).toString();
+				return newAreaURI.append(areaURI.substring(0, subStringEndIndex)).append(areaId).toString();
 			}
 		}
-		throw new IllegalStateException("Character is in the unknown area.");
+		return "";
 	}
 
 	private void updateEmoteType(EmoteState.EmoteType animationClassToStart) {
 		this.emoteState.setEmoteType(animationClassToStart);
 	}
 
-	public void deletePlayer() {
+	public void destroyPlayer() {
 		writeCharacterData(characterURI);
 	}
 
 	private void writeCharacterData(String characterURI) {
 		Character character = getCharacter(characterURI);
-		character.setPosition(position);
-		character.setAngle(angle);
-		character.setAreaURI(areaURI);
+		character.update(position, angle, null, areaURI); // model(��3����)�̍X�V�͏o���Ȃ�
 	}
 }