diff --git a/src/main/java/emu/grasscutter/data/GenshinData.java b/src/main/java/emu/grasscutter/data/GenshinData.java
index 7e14b1b46..155ebb60c 100644
--- a/src/main/java/emu/grasscutter/data/GenshinData.java
+++ b/src/main/java/emu/grasscutter/data/GenshinData.java
@@ -31,6 +31,7 @@ public class GenshinData {
 	private static final Int2ObjectMap<AvatarSkillDepotData> avatarSkillDepotDataMap = new Int2ObjectOpenHashMap<>();
 	private static final Int2ObjectMap<AvatarSkillData> avatarSkillDataMap = new Int2ObjectOpenHashMap<>();
 	private static final Int2ObjectMap<AvatarCurveData> avatarCurveDataMap = new Int2ObjectLinkedOpenHashMap<>();
+	private static final Int2ObjectMap<AvatarFetterLevelData> avatarFetterLevelDataMap = new Int2ObjectOpenHashMap<>();
 	private static final Int2ObjectMap<AvatarPromoteData> avatarPromoteDataMap = new Int2ObjectOpenHashMap<>();
 	private static final Int2ObjectMap<AvatarTalentData> avatarTalentDataMap = new Int2ObjectOpenHashMap<>();
 	private static final Int2ObjectMap<ProudSkillData> proudSkillDataMap = new Int2ObjectOpenHashMap<>();
@@ -114,6 +115,10 @@ public class GenshinData {
 		return playerLevelDataMap;
 	}
 
+	public static Int2ObjectMap<AvatarFetterLevelData> getAvatarFetterLevelDataMap() {
+		return avatarFetterLevelDataMap;
+	}
+
 	public static Int2ObjectMap<AvatarLevelData> getAvatarLevelDataMap() {
 		return avatarLevelDataMap;
 	}
@@ -175,6 +180,11 @@ public class GenshinData {
 		AvatarLevelData levelData = avatarLevelDataMap.get(level);
 		return levelData != null ? levelData.getExp() : 0;
 	}
+
+	public static int getAvatarFetterLevelExpRequired(int level) {
+		AvatarFetterLevelData levelData = avatarFetterLevelDataMap.get(level);
+		return levelData != null ? levelData.getExp() : 0;
+	}
 	
 	public static Int2ObjectMap<ProudSkillData> getProudSkillDataMap() {
 		return proudSkillDataMap;
diff --git a/src/main/java/emu/grasscutter/data/def/AvatarFetterLevelData.java b/src/main/java/emu/grasscutter/data/def/AvatarFetterLevelData.java
new file mode 100644
index 000000000..8dd93eea5
--- /dev/null
+++ b/src/main/java/emu/grasscutter/data/def/AvatarFetterLevelData.java
@@ -0,0 +1,23 @@
+package emu.grasscutter.data.def;
+
+import emu.grasscutter.data.GenshinResource;
+import emu.grasscutter.data.ResourceType;
+
+@ResourceType(name = "AvatarFettersLevelExcelConfigData.json")
+public class AvatarFetterLevelData extends GenshinResource {
+	private int FetterLevel;
+	private int NeedExp;
+	
+	@Override
+	public int getId() {
+		return this.FetterLevel;
+	}
+	
+	public int getLevel() {
+		return FetterLevel;
+	}
+	
+	public int getExp() {
+		return NeedExp;
+	}
+}
diff --git a/src/main/java/emu/grasscutter/game/avatar/GenshinAvatar.java b/src/main/java/emu/grasscutter/game/avatar/GenshinAvatar.java
index 6906d3896..d4e998d46 100644
--- a/src/main/java/emu/grasscutter/game/avatar/GenshinAvatar.java
+++ b/src/main/java/emu/grasscutter/game/avatar/GenshinAvatar.java
@@ -89,6 +89,9 @@ public class GenshinAvatar {
 	private int flyCloak;
 	private int costume;
 	private int bornTime;
+
+	private int fetterLevel = 1;
+	private int fetterExp;
 	
 	public GenshinAvatar() {
 		// Morhpia only!
@@ -281,6 +284,22 @@ public class GenshinAvatar {
 		return fetters;
 	}
 
+	public int getFetterLevel() {
+		return fetterLevel;
+	}
+
+	public void setFetterLevel(int fetterLevel) {
+		this.fetterLevel = fetterLevel;
+	}
+
+	public int getFetterExp() {
+		return fetterExp;
+	}
+
+	public void setFetterExp(int fetterExp) {
+		this.fetterExp = fetterExp;
+	}
+
 	public float getCurrentHp() {
 		return currentHp;
 	}
@@ -702,8 +721,8 @@ public class GenshinAvatar {
 	
 	public AvatarInfo toProto() {
 		AvatarFetterInfo.Builder avatarFetter = AvatarFetterInfo.newBuilder()
-				.setExpLevel(10)
-				.setExpNumber(6325); // Highest Level
+				.setExpLevel(this.getFetterLevel())
+				.setExpNumber(this.getFetterExp());
 		
 		if (this.getFetterList() != null) {
 			for (int i = 0; i < this.getFetterList().size(); i++) {
diff --git a/src/main/java/emu/grasscutter/game/managers/InventoryManager.java b/src/main/java/emu/grasscutter/game/managers/InventoryManager.java
index 532155db1..96ab032b8 100644
--- a/src/main/java/emu/grasscutter/game/managers/InventoryManager.java
+++ b/src/main/java/emu/grasscutter/game/managers/InventoryManager.java
@@ -711,6 +711,31 @@ public class InventoryManager {
 		player.sendPacket(new PacketAvatarUpgradeRsp(avatar, oldLevel, oldPropMap));
 	}
 
+	public void upgradeAvatarFetterLevel(GenshinPlayer player, GenshinAvatar avatar, int expGain) {
+		// May work. Not test.
+		int maxLevel = GenshinData.getAvatarFetterLevelDataMap().get(GenshinData.getAvatarFetterLevelDataMap().size() - 1).getLevel();
+		int level = avatar.getFetterLevel();
+		int exp = avatar.getFetterExp();
+		int reqExp = GenshinData.getAvatarFetterLevelExpRequired(level);
+
+		while (expGain > 0 && reqExp > 0 && level < maxLevel) {
+			int toGain = Math.min(expGain, reqExp - exp);
+			exp += toGain;
+			expGain -= toGain;
+			if (exp >= reqExp) {
+				exp = 0;
+				level += 1;
+				reqExp = GenshinData.getAvatarFetterLevelExpRequired(level);
+			}
+		}
+		
+		avatar.setFetterLevel(level);
+		avatar.setFetterExp(exp);
+		avatar.save();
+		
+		player.sendPacket(new PacketAvatarPropNotify(avatar));
+	}
+
 	public void upgradeAvatarSkill(GenshinPlayer player, long guid, int skillId) {
 		// Sanity checks
 		GenshinAvatar avatar = player.getAvatars().getAvatarByGuid(guid);