diff --git a/battle/entity/Entity.java b/battle/entity/Entity.java
index 087b34b4..0e693903 100755
--- a/battle/entity/Entity.java
+++ b/battle/entity/Entity.java
@@ -21,9 +21,11 @@
 import common.util.pack.EffAnim;
 import common.util.pack.EffAnim.*;
 import common.util.pack.Soul;
+import common.util.stage.Music;
 import common.util.stage.StageLimit;
 import common.util.unit.Level;
 import common.util.unit.Trait;
+import io.BCMusic;
 
 import java.util.*;
 
diff --git a/io/assets/Admin.java b/io/assets/Admin.java
index 070c4bb4..89ba7b47 100644
--- a/io/assets/Admin.java
+++ b/io/assets/Admin.java
@@ -89,6 +89,9 @@ public void initProfile() {
 			UserProfile.getBCData().load((str) -> {
 			}, (d) -> {
 			});
+			UserProfile.getBCUData().load((str) -> {
+			}, (d) -> {
+			});
 			BasisSet.read();
 			// UserProfile.loadPacks(); TODO
 		}
diff --git a/io/assets/UpdateCheck.java b/io/assets/UpdateCheck.java
index 4884b6b4..89f133da 100644
--- a/io/assets/UpdateCheck.java
+++ b/io/assets/UpdateCheck.java
@@ -116,6 +116,7 @@ public static class AnnouncementJson {
 		public ApkJson[] apk_update;
 		public long text_update;
 		public int music;
+		public int customMusic;
 
 	}
 
@@ -246,6 +247,33 @@ public static List<Downloader> checkNewMusic(int count) {
 		return ans;
 	}
 
+	public static List<Downloader> checkNewCustomMusic(int count) {
+		boolean[] exists = new boolean[count];
+		File musicFolder = CommonStatic.ctx.getAssetFile("./music/");
+		if (musicFolder.exists()) {
+			File[] musicList = musicFolder.listFiles();
+
+			if (musicList != null) {
+				for (File music : musicList)
+					if (music.getName().length() == 9 && music.getName().endsWith("_c.ogg")) {
+						int id = CommonStatic.parseIntN(music.getName());
+						if (id < count && id != -1) // prevents array index out of bounds
+							exists[id] = true;
+					}
+			}
+		}
+		List<Downloader> ans = new ArrayList<>();
+		for (int i = 0; i < count; i++)
+			if (!exists[i]) {
+				File target = CommonStatic.ctx.getAssetFile("./music/" + Data.trio(i) + "_c.ogg");
+				File temp = CommonStatic.ctx.getAssetFile("./music/_c.ogg.temp");
+				String url = URL_MUSIC + Data.trio(i) + "_c.ogg";
+				ans.add(new Downloader(target, temp, "bcu custom music " + Data.trio(i), false, url));
+				System.out.println("bcu custom music " + Data.trio(i));
+			}
+		return ans;
+	}
+
 	public static Context.SupExc<List<Downloader>> checkMusic(int count) {
 		return () -> {
 			boolean[] exi = new boolean[count];
diff --git a/pack/Identifier.java b/pack/Identifier.java
index 808d4b79..cdd12bd6 100644
--- a/pack/Identifier.java
+++ b/pack/Identifier.java
@@ -22,6 +22,7 @@
 public class Identifier<T extends IndexContainer.Indexable<?, T>> implements Comparable<Identifier<?>>, Cloneable {
 
 	public static final String DEF = "000000";
+	public static final String BCU = "000001";
 
 	@Nullable
 	public static <T extends IndexContainer.Indexable<?, T>> T get(Identifier<T> id) {
diff --git a/pack/PackData.java b/pack/PackData.java
index 3e601b81..ae7a677d 100644
--- a/pack/PackData.java
+++ b/pack/PackData.java
@@ -276,6 +276,50 @@ private void loadUnits(Consumer<Double> bar) {
 
     }
 
+    public static class DefBcuPack extends PackData {
+
+        public VFileRoot root = new VFileRoot(".");
+
+        protected DefBcuPack() {
+
+        }
+
+        @Override
+        public String getSID() {
+            return Identifier.BCU;
+        }
+
+        public void load(Consumer<String> progress, Consumer<Double> bar) {
+            System.out.println("LOADING BCU DATA");
+            progress.accept("loading BCU musics");
+            loadMusic();
+        }
+
+        @Override
+        public String toString() {
+            return "Custom BCU Data";
+        }
+
+        private void loadMusic() {
+            File dict = CommonStatic.ctx.getAssetFile("./music/");
+            if (!dict.exists())
+                return;
+            File[] fs = dict.listFiles();
+            for (File f : fs) {
+                String str = f.getName();
+                if (str.length() != 9)
+                    continue;
+                if (!str.endsWith("_c.ogg"))
+                    continue;
+                int id = CommonStatic.parseIntN(str.substring(0, 3));
+                if (id == -1)
+                    continue;
+                System.out.println("Loaded " + str + " as custom");
+                musics.set(id, new Music(new Identifier<>(Identifier.BCU, Music.class, id), 0, new FDFile(f)));
+            }
+        }
+    }
+
     @JsonClass(noTag = NoTag.LOAD)
     public static class PackDesc {
         public String BCU_VERSION;
diff --git a/pack/UserProfile.java b/pack/UserProfile.java
index 4c190760..b8b64d42 100644
--- a/pack/UserProfile.java
+++ b/pack/UserProfile.java
@@ -71,11 +71,12 @@ public static <T> List<T> getAll(String pack, Class<T> cls) {
 	}
 
 	/**
-	 * get all packs, including default pack
+	 * get all packs, including default and bcu pack
 	 */
 	public static Collection<PackData> getAllPacks() {
 		List<PackData> ans = new ArrayList<>();
 		ans.add(getBCData());
+		ans.add(getBCUData());
 		ans.addAll(getUserPacks());
 		return ans;
 	}
@@ -84,6 +85,10 @@ public static DefPack getBCData() {
 		return profile().def;
 	}
 
+	public static PackData.DefBcuPack getBCUData() {
+		return profile().defbcu;
+	}
+
 	/**
 	 * get a PackData from a String
 	 */
@@ -345,6 +350,7 @@ public static void unregister(String id) {
 	}
 
 	public final DefPack def = new DefPack();
+	public final PackData.DefBcuPack defbcu = new PackData.DefBcuPack();
 	public final Map<String, UserPack> packmap = new HashMap<>();
 
 	public final Set<UserPack> packlist = new HashSet<>();