diff --git a/ArcFormats/ArcFormats.csproj b/ArcFormats/ArcFormats.csproj
index 98221e8b..dea17ec0 100644
--- a/ArcFormats/ArcFormats.csproj
+++ b/ArcFormats/ArcFormats.csproj
@@ -64,6 +64,7 @@
     <Compile Include="Amaterasu\ImageGRP.cs" />
     <Compile Include="ArcMiris.cs" />
     <Compile Include="BitStream.cs" />
+    <Compile Include="Debonosu\ArcPAK.cs" />
     <Compile Include="Emic\ArcPACK.cs" />
     <Compile Include="Emic\ImageMWP.cs" />
     <Compile Include="Ethornell\AudioBGI.cs" />
diff --git a/ArcFormats/Debonosu/ArcPAK.cs b/ArcFormats/Debonosu/ArcPAK.cs
new file mode 100644
index 00000000..f213be42
--- /dev/null
+++ b/ArcFormats/Debonosu/ArcPAK.cs
@@ -0,0 +1,150 @@
+//! \file       ArcPAK.cs
+//! \date       Sat Sep 19 08:51:36 2015
+//! \brief      Debonosu Works resource archive.
+//
+// Copyright (C) 2015 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.IO;
+using System.IO.Compression;
+using GameRes.Utility;
+
+namespace GameRes.Formats.Debonosu
+{
+    [Export(typeof(ArchiveFormat))]
+    public class PakOpener : ArchiveFormat
+    {
+        public override string         Tag { get { return "PAK/Debonosu"; } }
+        public override string Description { get { return "Debonosu Works resource archive"; } }
+        public override uint     Signature { get { return 0x004B4150; } } // 'PAK'
+        public override bool  IsHierarchic { get { return true; } }
+        public override bool     CanCreate { get { return false; } }
+
+        public override ArcFile TryOpen (ArcView file)
+        {
+            uint index_offset = file.View.ReadUInt16 (4);
+            if (0 != file.View.ReadUInt16 (10))
+                return null;
+
+            uint info_size = file.View.ReadUInt32 (index_offset);
+            int root_count = file.View.ReadInt32 (index_offset+8);
+            uint unpacked_size = file.View.ReadUInt32 (index_offset+0xC);
+            uint packed_size = file.View.ReadUInt32 (index_offset+0x10);
+            using (var packed = file.CreateStream (index_offset+info_size, packed_size))
+            using (var unpacked = new DeflateStream (packed, CompressionMode.Decompress))
+            using (var reader = new IndexReader (unpacked, index_offset+info_size+packed_size))
+            {
+                var dir = reader.ReadRoot (root_count);
+                if (null == dir)
+                    return null;
+                return new ArcFile (file, this, dir);
+            }
+        }
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            var input = arc.File.CreateStream (entry.Offset, entry.Size);
+            var packed = entry as PackedEntry;
+            if (null == packed || !packed.IsPacked)
+                return input;
+            return new DeflateStream (input, CompressionMode.Decompress);
+        }
+
+        internal sealed class IndexReader : IDisposable
+        {
+            BinaryReader    m_input;
+            long            m_base_offset;
+            List<Entry>     m_dir = new List<Entry>();
+
+            public IndexReader (Stream input, long base_offset)
+            {
+                m_input = new ArcView.Reader (input);
+                m_base_offset = base_offset;
+            }
+
+            public List<Entry> ReadRoot (int root_count)
+            {
+                ReadDir ("", root_count);
+                return m_dir;
+            }
+
+            void ReadDir (string path, int count)
+            {
+                for (int i = 0; i < count; ++i)
+                {
+                    long offset = m_input.ReadInt64();
+                    long unpacked = m_input.ReadInt64();
+                    long packed = m_input.ReadInt64();
+                    uint flags = m_input.ReadUInt32();
+                    m_input.ReadUInt64(); // ctime
+                    m_input.ReadUInt64(); // atime
+                    m_input.ReadUInt64(); // mtime
+                    var name = Path.Combine (path, ReadName());
+                    if (0 != (flags & 0x10))
+                    {
+                        ReadDir (name, (int)unpacked);
+                    }
+                    else
+                    {
+                        var entry = FormatCatalog.Instance.Create<PackedEntry> (name);
+                        entry.Offset = m_base_offset + offset;
+                        entry.Size = (uint)packed;
+                        entry.UnpackedSize = (uint)unpacked;
+                        entry.IsPacked = true;
+                        m_dir.Add (entry);
+                    }
+                }
+            }
+
+            byte[] name_buffer = new byte[32];
+
+            string ReadName ()
+            {
+                int size = 0;
+                for (;;)
+                {
+                    int b = m_input.ReadByte();
+                    if (0 == b)
+                        break;
+                    if (name_buffer.Length == size)
+                    {
+                        Array.Resize (ref name_buffer, checked(size/2*3));
+                    }
+                    name_buffer[size++] = (byte)b;
+                }
+                return Encodings.cp932.GetString (name_buffer, 0, size);
+            }
+
+            bool _disposed = false;
+            public void Dispose ()
+            {
+                if (!_disposed)
+                {
+                    m_input.Dispose();
+                    _disposed = true;
+                }
+            }
+        }
+    }
+}
diff --git a/supported.html b/supported.html
index 596cd44c..298e783f 100644
--- a/supported.html
+++ b/supported.html
@@ -380,6 +380,9 @@ Futamajo<br/>
 <tr class="odd"><td>*.bmp</td><td><tt>MWP</tt></td><td>No</td></tr>
 <tr><td>*.dat+*l.dat</td><td>-</td><td>No</td><td>Studio Miris</td><td>Tetsuwan Gacchu!</td></tr>
 <tr class="odd"><td>*.bdf<br/>*.spl</td><td>-</td><td>No</td><td>Zyx</td><td>Innai Kansen series</td></tr>
+<tr><td>*.pak</td><td><tt>PAK</tt></td><td>No</td><td>Debonosu Works</td><td>
+Gigai no Alruna<br/>
+</td></tr>
 </table>
 <p><a name="note-1" class="footnote">1</a> Non-encrypted only</p>
 </body>