diff --git a/ArcFormats/ArcFormats.csproj b/ArcFormats/ArcFormats.csproj
index b30669be..b615f40e 100644
--- a/ArcFormats/ArcFormats.csproj
+++ b/ArcFormats/ArcFormats.csproj
@@ -483,6 +483,7 @@
     </None>
     <None Include="WebP\Lossless.cs" />
     <Compile Include="Risa\ImageSYG.cs" />
+    <Compile Include="VnSystem\ArcVFS.cs" />
     <Compile Include="Will\ArcPNA.cs" />
     <Compile Include="Will\ArcPulltop.cs" />
     <Compile Include="Will\ArcWIP.cs" />
diff --git a/ArcFormats/VnSystem/ArcVFS.cs b/ArcFormats/VnSystem/ArcVFS.cs
new file mode 100644
index 00000000..ee024d82
--- /dev/null
+++ b/ArcFormats/VnSystem/ArcVFS.cs
@@ -0,0 +1,127 @@
+//! \file       ArcVFS.cs
+//! \date       Wed Jan 18 21:30:30 2017
+//! \brief      VNSystem engine resource archive.
+//
+// Copyright (C) 2017 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.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.IO;
+
+namespace GameRes.Formats.VnSystem
+{
+    [Export(typeof(ArchiveFormat))]
+    public class VfsOpener : ArchiveFormat
+    {
+        public override string         Tag { get { return "VFS/VNSYSTEM"; } }
+        public override string Description { get { return "VNSystem engine resource archive"; } }
+        public override uint     Signature { get { return 0x20534656; } } // 'VFS File'
+        public override bool  IsHierarchic { get { return false; } }
+        public override bool      CanWrite { get { return false; } }
+
+        public override ArcFile TryOpen (ArcView file)
+        {
+            if (!file.View.AsciiEqual (4, "File"))
+                return null;
+            bool is_compressed = file.View.ReadInt32 (8) != 0;
+            int count = file.View.ReadInt32 (12);
+            if (!IsSaneCount (count))
+                return null;
+
+            uint index_offset = 0x10;
+            long data_offset = index_offset + count * 0x1C;
+            var dir = new List<Entry> (count);
+            for (int i = 0; i < count; ++i)
+            {
+                var name = file.View.ReadString (index_offset, 0x14);
+                index_offset += 0x14;
+                var entry = FormatCatalog.Instance.Create<PackedEntry> (name);
+                entry.Offset = data_offset + file.View.ReadUInt32 (index_offset);
+                entry.Size = file.View.ReadUInt32 (index_offset+4);
+                if (!entry.CheckPlacement (file.MaxOffset))
+                    return null;
+                entry.IsPacked = is_compressed;
+                dir.Add (entry);
+                index_offset += 8;
+            }
+            return new ArcFile (file, this, dir);
+        }
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            var pent = entry as PackedEntry;
+            if (null == pent || !pent.IsPacked)
+                return arc.File.CreateStream (entry.Offset, entry.Size);
+            if (0 == pent.UnpackedSize)
+                pent.UnpackedSize = arc.File.View.ReadUInt32 (entry.Offset);
+            using (var input = arc.File.CreateStream (entry.Offset+4, entry.Size-4))
+            {
+                var data = UnpackEntry (input, pent.UnpackedSize);
+                return new BinMemoryStream (data, entry.Name);
+            }
+        }
+
+        byte[] UnpackEntry (Stream input, uint unpacked_size)
+        {
+            const int dict_size = 0x10;
+            var output = new byte[unpacked_size];
+            using (var bits = new MsbBitStream (input, true))
+            {
+                var dict = new byte[dict_size];
+                int dict_pos = 0;
+                for (int dst = 0; dst < output.Length; ++dst)
+                {
+                    byte cur_byte;
+                    if (bits.GetNextBit() != 0)
+                    {
+                        int offset = GetBitLength (bits);
+                        int pos = dict_pos - offset;
+                        if (pos < 0)
+                            pos += dict_size;
+                        if (pos < 0 || pos >= dict_size)
+                            throw new InvalidDataException ("Invalid compressed data.");
+                        cur_byte = dict[pos];
+                    }
+                    else
+                    {
+                        cur_byte = (byte)bits.GetBits (8);
+                    }
+                    output[dst] = cur_byte;
+                    dict[dict_pos++] = cur_byte;
+                    dict_pos &= 0xF;
+                }
+            }
+            return output;
+        }
+
+        static int GetBitLength (IBitStream input)
+        {
+            int count = 0;
+            while (0 == input.GetNextBit())
+                ++count;
+            int n = 1 << count;
+            if (count > 0)
+                n |= input.GetBits (count);
+            return n;
+        }
+    }
+}
diff --git a/supported.html b/supported.html
index ec00af5d..524c6e18 100644
--- a/supported.html
+++ b/supported.html
@@ -590,6 +590,7 @@ Zettai Joshi Ryouiki!<br/>
 Bishoku<br/>
 Dungeon Crusaderz ~Tales of Demon Eater~<br/>
 Dungeon Crusaderz 2 ~Eigou no Rakudo~<br/>
+Hitozuma Cosplay Kissa<br/>
 Inkou Haden Amatsu ~Hakudaku no Juin~<br/>
 Magical Witch Academy<br/>
 Magical Witch Concerto<br/>
@@ -1336,6 +1337,9 @@ Onepapa ~Onegai PaPa!~<br/>
 Summer Radish Vacation!!<br/>
 </td></tr>
 <tr><td>*.cgd<br/>*.bgd<br/>*.chr</td><td>-</td><td>No</td></tr>
+<tr class="odd"><td>*.vfs</td><td><tt>VFS File</tt></td><td>No</td><td>VNSystem</td><td>
+Seika no Mori<br/>
+</td></tr>
 </table>
 <p><a name="note-1" class="footnote">1</a> Non-encrypted only</p>
 </body>