diff --git a/ArcFormats/KiriKiri/CryptAlgorithms.cs b/ArcFormats/KiriKiri/CryptAlgorithms.cs
index 8e1149ad..a94e8262 100644
--- a/ArcFormats/KiriKiri/CryptAlgorithms.cs
+++ b/ArcFormats/KiriKiri/CryptAlgorithms.cs
@@ -1406,4 +1406,91 @@ namespace GameRes.Formats.KiriKiri
             return key;
         }
     }
+
+    [Serializable]
+    public class NinkiSeiyuuCrypt : ICrypt
+    {
+        ulong m_key1;
+        ulong m_key2;
+        ulong m_key3;
+
+        byte[] m_tbl2;
+        byte[] m_tbl3;
+
+        public NinkiSeiyuuCrypt(ulong key1, ulong key2, ulong key3)
+        {
+            m_key1 = key1;
+            m_key2 = key2;
+            m_key3 = key3;
+
+            m_tbl2 = GetTable2(3080);
+            m_tbl3 = GetTable3(3080, m_key1, m_key2, m_key3);
+        }
+
+        static byte[] GetTable1(uint seed)
+        {
+            var key = new byte[32];
+
+            uint v48 = seed & 0x7FFFFFFF;
+
+            for (var i = 0; i < 31; i++)
+            {
+                key[i] = (byte)v48;
+                v48 = (v48 >> 8) | (uint)((byte)v48 << 23);
+            }
+
+            return key;
+        }
+
+        static byte[] GetTable2(uint seed)
+        {
+            var key = new byte[64];
+
+            uint v51 = seed & 0xFFF;
+            ulong v52 = (ulong)(v51 | (v51 << 13)) | ((ulong)(v51 >> 19) << 32);
+            uint v53 = v51 | ((uint)v52 << 13);
+            uint v54 = (uint)((ulong)(((uint)v52 << 7) & 0x1FFFFFFF) | (v52 >> 19));
+
+            for (int i = 0; i < 61; i++)
+            {
+                var v56 = (byte)v53;
+                key[i] = (byte)v53;
+                v53 = (uint)((((ulong)v54 << 32) | v53) >> 8);
+                v54 = (v54 >> 8) | (uint)(v56 << 21);
+            }
+
+            return key;
+        }
+
+        static byte[] GetTable3(uint seed, ulong key1, ulong key2, ulong key3)
+        {
+            var key = new byte[64];
+
+            uint v88 = seed & 0xFFF;
+            ulong v89 = (ulong)(v88 | (v88 << 13)) | ((ulong)(v88 >> 19) << 32);
+            uint v90 = (uint)((key1 + key2) ^ (ulong)(v88 | ((uint)v89 << 13)));
+            uint v91 = (uint)((ulong)(((key1 + ((key3 & 0xFFFFFFFF00000000) | (key2 & 0xFFFFFFFF))) >> 32) & 0x1FFFFFFF) ^ ((ulong)(((uint)v89 << 7) & 0x1FFFFFFF) | (v89 >> 19)));
+
+            for (int i = 0; i < 61; i++)
+            {
+                var v93 = (byte)v90;
+                key[i] = (byte)v90;
+                v90 = (uint)((((ulong)v91 << 32) | v90) >> 8);
+                v91 = (v91 >> 8) | (uint)(v93 << 21);
+            }
+
+            return key;
+        }
+
+        public override void Decrypt(Xp3Entry entry, long offset, byte[] buffer, int pos, int count)
+        {
+            var tbl1 = GetTable1(entry.Hash);
+
+            for (var i = 0; i < count; i++)
+            {
+                buffer[pos + i] ^= tbl1[(offset + i) % 0x1F];
+                buffer[pos + i] += (byte)(m_tbl2[(offset + i) % 0x3D] ^ m_tbl3[(offset + i) % 0x3D]);
+            }
+        }
+    }
 }
diff --git a/ArcFormats/Resources/Formats.dat b/ArcFormats/Resources/Formats.dat
index b8cd78b3..64830f2f 100644
Binary files a/ArcFormats/Resources/Formats.dat and b/ArcFormats/Resources/Formats.dat differ