diff --git a/src-ui/changes.html b/src-ui/changes.html
index 12bafc355..6b8be4e15 100644
--- a/src-ui/changes.html
+++ b/src-ui/changes.html
@@ -33,6 +33,7 @@
 <main>
 <div style="margin-bottom: 5px;"><b>Latest types</b> (<em><a href="/list.html" target="_parent">all types</a></em>)</div>
 <ul>
+  <li><a href="/p?patchwork" target="_parent">Patchwork パッチワーク</a></li>
   <li><a href="/p?myopia" target="_parent">Myopia</a></li>
   <li><a href="/p?sashikazune" target="_parent">Sashikazune さしカズね</a></li>
   <li><a href="/p?brownies" target="_parent">Brownies ブラウニー</a></li>
@@ -40,7 +41,6 @@
   <li><a href="/p?bdwalk" target="_parent">Building Walk ビルウォーク <small>(rules update)</small></a></li>
   <li><a href="/p?heyapin" target="_parent">Heyapin へやピン</a></li>
   <li><a href="/p?invlitso" target="_parent">Inverse LITSO</a></li>
-  <li><a href="/p?battleship" target="_parent">Battleship</a></li>
 </ul>
 </main>
 </body>
diff --git a/src-ui/img/patchwork.png b/src-ui/img/patchwork.png
new file mode 100644
index 000000000..352a821cf
Binary files /dev/null and b/src-ui/img/patchwork.png differ
diff --git a/src-ui/js/ui/KeyPopup.js b/src-ui/js/ui/KeyPopup.js
index d623ca4a4..9cf0fed8a 100644
--- a/src-ui/js/ui/KeyPopup.js
+++ b/src-ui/js/ui/KeyPopup.js
@@ -180,7 +180,8 @@ ui.keypopup = {
 		maxi: [10, 0],
 		tetrochain: [10, 0],
 		brownies: [127, 0],
-		sashikazune: [10, 0]
+		sashikazune: [10, 0],
+		patchwork: [10, 0]
 	},
 
 	//---------------------------------------------------------------------------
@@ -397,6 +398,11 @@ ui.keypopup = {
 			cap = "□";
 		} else if (pid === "rectslider") {
 			cap = "■";
+		} else if (pid === "patchwork") {
+			cap = {
+				text: "■",
+				color: "rgb(204,204,204)"
+			};
 		} else if (
 			pid === "kurotto" ||
 			pid === "bonsan" ||
diff --git a/src-ui/js/ui/Misc.js b/src-ui/js/ui/Misc.js
index 1efe9ed4a..55a6f7eb2 100755
--- a/src-ui/js/ui/Misc.js
+++ b/src-ui/js/ui/Misc.js
@@ -157,6 +157,7 @@ function toBGimage(pid) {
 		"oneroom",
 		"ovotovata",
 		"oyakodori",
+		"patchwork",
 		"pencils",
 		"pentopia",
 		"ququ",
diff --git a/src-ui/list.html b/src-ui/list.html
index 0716d98c7..67a7fe447 100644
--- a/src-ui/list.html
+++ b/src-ui/list.html
@@ -75,6 +75,7 @@ <h2 id="title"><span lang="ja">パズルの種類のリスト</span><span lang="
     <li data-pid="cocktail"></li>
     <li data-pid="kuroclone"></li>
     <li data-pid="martini"></li>
+    <li data-pid="patchwork"></li>
    </ul>
   </div>
   <div class="lists blocks">
diff --git a/src/pzpr/variety.js b/src/pzpr/variety.js
index e43d6855a..0c7379452 100755
--- a/src/pzpr/variety.js
+++ b/src/pzpr/variety.js
@@ -285,6 +285,7 @@
 			oyakodori: [0, 0, "おやこどり", "Oyakodori", "kaero"],
 			paintarea: [1, 0, "ペイントエリア", "Paintarea"],
 			parquet: [0, 0, "Parquet", "Parquet"],
+			patchwork: [0, 0, "パッチワーク", "Patchwork"],
 			pencils: [0, 0, "ペンシルズ", "Pencils"],
 			pentominous: [0, 0, "Pentominous", "Pentominous", "fillomino"],
 			pentopia: [0, 0, "Pentopia", "Pentopia", "statuepark"],
diff --git a/src/res/failcode.en.json b/src/res/failcode.en.json
index fc3ac1661..0ee022e1f 100644
--- a/src/res/failcode.en.json
+++ b/src/res/failcode.en.json
@@ -168,7 +168,7 @@
     "bkNotRect": "There is a room whose shape is not a rectangle.",
     "bkNotRect3.shikaku": "An area whose size is not a multiple of three is not a rectangle.",
     "bkNotSeqNum.renban": "The numbers in the room are not consecutive.",
-    "bkNotSquare.squarejam": "An area is not a square.",
+    "bkNotSquare": "An area is not a square.",
     "bkNotSquare.tatamibari": "A tatami is not a square.",
     "bkNotSymmRoom.fillomino": "An area is not point symmetric.",
     "bkNotSymRoom.ayeheya": "The room is not point symmetric.",
@@ -316,6 +316,7 @@
     "cbSameNum.nanro": "Adjacent blocks have the same number.",
     "cbShade.shimaguni": "Countries in different marine areas are adjacent.",
     "cbShade": "Shaded cells are adjacent over a border.",
+    "cbUnshade": "Unshaded cells are adjacent over a border.",
     "ceAddLine": "A cell with given lines has extra lines.",
     "ceDark.lightup": "A cell is not shined.",
     "ceDirection.compass": "The number of cells in the direction is wrong.",
diff --git a/src/res/failcode.ja.json b/src/res/failcode.ja.json
index 1adcc2025..035cc3855 100644
--- a/src/res/failcode.ja.json
+++ b/src/res/failcode.ja.json
@@ -657,7 +657,7 @@
     "nmLoop.snakepit": "スネークに端がありません。",
     "nmMidpoint.snakepit": "灰色のマスがスネークの端になっています。",
     "nmSame2x2.snakepit": "スネークが自分自身とタテヨコに接しています。",
-    "bkNotSquare.squarejam": "領域が正方形ではありません。",
+    "bkNotSquare": "領域が正方形ではありません。",
     "anShadeNe.yajisoko": "箱の数が正しくありません。",
     "bkSideNe.squarejam": "数字と領域の大きさが異なります。",
     "laOnNum.yajisoko": "線が箱を通り過ぎています。",
diff --git a/src/variety-common/Graphic.js b/src/variety-common/Graphic.js
index ab7cbafea..9d9821b71 100644
--- a/src/variety-common/Graphic.js
+++ b/src/variety-common/Graphic.js
@@ -1116,31 +1116,31 @@ pzpr.classmgr.makeCommon({
 					var LTin = cell.bx > 2,
 						RTin = cell.bx < 2 * this.board.cols - 2;
 
-					var isUP = !UPin || adb.top.ques === 1;
-					var isDN = !DNin || adb.bottom.ques === 1;
-					var isLT = !LTin || adb.left.ques === 1;
-					var isRT = !RTin || adb.right.ques === 1;
+					var isUP = !UPin || adb.top.isBorder();
+					var isDN = !DNin || adb.bottom.isBorder();
+					var isLT = !LTin || adb.left.isBorder();
+					var isRT = !RTin || adb.right.isBorder();
 
 					var isUL =
-						!UPin ||
-						!LTin ||
-						cell.relbd(-2, -1).ques === 1 ||
-						cell.relbd(-1, -2).ques === 1;
+						isUP ||
+						isLT ||
+						cell.relbd(-2, -1).isBorder() ||
+						cell.relbd(-1, -2).isBorder();
 					var isUR =
-						!UPin ||
-						!RTin ||
-						cell.relbd(2, -1).ques === 1 ||
-						cell.relbd(1, -2).ques === 1;
+						isUP ||
+						isRT ||
+						cell.relbd(2, -1).isBorder() ||
+						cell.relbd(1, -2).isBorder();
 					var isDL =
-						!DNin ||
-						!LTin ||
-						cell.relbd(-2, 1).ques === 1 ||
-						cell.relbd(-1, 2).ques === 1;
+						isDN ||
+						isLT ||
+						cell.relbd(-2, 1).isBorder() ||
+						cell.relbd(-1, 2).isBorder();
 					var isDR =
-						!DNin ||
-						!RTin ||
-						cell.relbd(2, 1).ques === 1 ||
-						cell.relbd(1, 2).ques === 1;
+						isDN ||
+						isRT ||
+						cell.relbd(2, 1).isBorder() ||
+						cell.relbd(1, 2).isBorder();
 
 					g.beginPath();
 
diff --git a/src/variety-common/MouseInput.js b/src/variety-common/MouseInput.js
index 46a558c9e..76c95a405 100644
--- a/src/variety-common/MouseInput.js
+++ b/src/variety-common/MouseInput.js
@@ -64,13 +64,16 @@ pzpr.classmgr.makeCommon({
 				this.inputData = cell.qans !== 1 ? 1 : 0;
 			} else if (this.inputMode === "unshade") {
 				this.inputData = cell.qsub !== 1 ? 2 : 0;
-			} else if (this.puzzle.getConfig("use") === 1) {
+			} else if (
+				this.puzzle.getConfig("use") === 1 &&
+				this.pid !== "patchwork"
+			) {
 				if (this.btn === "left") {
 					this.inputData = cell.qans !== 1 ? 1 : 0;
 				} else if (this.btn === "right") {
 					this.inputData = cell.qsub !== 1 ? 2 : 0;
 				}
-			} else if (this.puzzle.getConfig("use") === 2) {
+			} else {
 				if (!cell.allowShade()) {
 					this.inputData = cell.qsub !== 1 ? 2 : 0;
 				} else if (!cell.allowUnshade()) {
diff --git a/src/variety/patchwork.js b/src/variety/patchwork.js
new file mode 100644
index 000000000..866850314
--- /dev/null
+++ b/src/variety/patchwork.js
@@ -0,0 +1,213 @@
+//
+//  patchwork.js
+//
+(function(pidlist, classbase) {
+	if (typeof module === "object" && module.exports) {
+		module.exports = [pidlist, classbase];
+	} else {
+		pzpr.classmgr.makeCustom(pidlist, classbase);
+	}
+})(["patchwork"], {
+	//---------------------------------------------------------
+	// マウス入力系
+	MouseEvent: {
+		inputModes: {
+			edit: ["number", "undef", "clear"],
+			play: ["border", "shade", "unshade", "subline"]
+		},
+		mouseinput_auto: function() {
+			if (this.puzzle.playmode) {
+				if (this.mousestart || this.mousemove) {
+					if (this.btn === "right") {
+						this.inputQsubLine();
+					} else if (this.isBorderMode()) {
+						this.inputborder();
+					} else {
+						this.inputShade();
+					}
+				} else if (this.notInputted()) {
+					if (this.isBorderMode()) {
+						var border = this.getborder();
+						if (!border.isnull) {
+							border.setQsub(border.qsub === 1 ? 0 : 1);
+							border.draw();
+						}
+					} else if (this.btn === "right") {
+						this.inputShade();
+					}
+				}
+			} else if (this.puzzle.editmode) {
+				this.inputqnum();
+			}
+		}
+	},
+
+	//---------------------------------------------------------
+	// キーボード入力系
+	KeyEvent: {
+		enablemake: true
+	},
+
+	Cell: {
+		numberRemainsUnshaded: true,
+		minnum: 0,
+		maxnum: function() {
+			return this.board.cols * this.board.rows - 1;
+		}
+	},
+
+	Board: {
+		hasborder: 1
+	},
+
+	AreaRoomGraph: {
+		enabled: true
+	},
+
+	//---------------------------------------------------------
+	// 画像表示系
+
+	Graphic: {
+		hideHatena: true,
+		icecolor: "rgb(204,204,204)",
+		shadecolor: "#222222",
+		bordercolor_func: "qans",
+
+		paint: function() {
+			this.drawBGCells();
+			this.drawShadedCells();
+			this.drawDashedGrid();
+
+			this.drawQuesNumbers();
+
+			this.drawBorders();
+			this.drawBorderQsubs();
+
+			this.drawBoxBorders(false);
+			this.drawChassis();
+			this.drawTarget();
+		},
+
+		getBGCellColor: function(cell) {
+			if (cell.error === 1 || cell.qinfo === 1) {
+				if (cell.isNum()) {
+					return this.erricecolor;
+				} else {
+					return this.errbcolor1;
+				}
+			} else if (cell.isNum()) {
+				return this.icecolor;
+			} else if (cell.qsub === 1) {
+				return this.bcolor;
+			}
+			return null;
+		}
+	},
+
+	//---------------------------------------------------------
+	// URLエンコード/デコード処理
+	Encode: {
+		decodePzpr: function(type) {
+			this.decodeNumber16();
+		},
+		encodePzpr: function(type) {
+			this.encodeNumber16();
+		}
+	},
+
+	//---------------------------------------------------------
+	FileIO: {
+		decodeData: function() {
+			this.decodeCellQnumAns();
+			this.decodeBorderAns();
+		},
+		encodeData: function() {
+			this.encodeCellQnumAns();
+			this.encodeBorderAns();
+		}
+	},
+
+	//---------------------------------------------------------
+	// 正解判定処理実行部
+	AnsCheck: {
+		checklist: [
+			"checkSideAreaShadeCell",
+			"checkShadeCellCount",
+			"checkSideAreaUnshadeCell",
+			"checkRoomSquare",
+			"checkBorderDeadend+",
+			"doneShadingDecided"
+		],
+
+		checkShadeCellCount: function() {
+			var rooms = this.board.roommgr.components;
+			for (var r = 0; r < rooms.length; r++) {
+				var clist = rooms[r].clist,
+					d = clist.getRectSize();
+
+				if (d.rows !== d.cols || d.rows * d.cols !== d.cnt) {
+					continue;
+				}
+
+				var count = clist.filter(function(cell) {
+					return cell.isShade();
+				}).length;
+
+				for (var i = 0; i < clist.length; i++) {
+					var cell = clist[i];
+					var qnum = cell.qnum;
+					if (qnum < 0) {
+						continue;
+					}
+					if (qnum !== count) {
+						this.failcode.add("bkShadeNe");
+						if (this.checkOnly) {
+							return;
+						}
+						clist.seterr(1);
+					}
+				}
+			}
+		},
+
+		checkRoomSquare: function() {
+			this.checkAllArea(
+				this.board.roommgr,
+				function(w, h, a, n) {
+					return w === h && w * h === a;
+				},
+				"bkNotSquare"
+			);
+		},
+
+		checkSideAreaShadeCell: function() {
+			this.checkSideAreaCell(
+				function(cell1, cell2) {
+					return (
+						!cell1.isNum() &&
+						!cell2.isNum() &&
+						cell1.isShade() &&
+						cell2.isShade()
+					);
+				},
+				false,
+				"cbShade"
+			);
+		},
+
+		checkSideAreaUnshadeCell: function() {
+			this.checkSideAreaCell(
+				function(cell1, cell2) {
+					return (
+						!cell1.isNum() &&
+						!cell2.isNum() &&
+						!cell1.isShade() &&
+						!cell2.isShade()
+					);
+				},
+				false,
+				"cbUnshade"
+			);
+		}
+	}
+});
diff --git a/test/script/patchwork.js b/test/script/patchwork.js
new file mode 100644
index 000000000..7a4df563c
--- /dev/null
+++ b/test/script/patchwork.js
@@ -0,0 +1,53 @@
+/* patchwork.js */
+
+ui.debug.addDebugData("patchwork", {
+	url: "6/6/8j3i0m.i1h.i1.h0.g1",
+	failcheck: [
+		[
+			"cbShade",
+			"pzprv3/patchwork/6/6/8 # # . . 3 /# # # 0 . . /# # # . . - /. . # 1 . . /- . . . 1 - /. . 0 - . 1 /0 0 1 0 0 /0 0 1 0 0 /0 0 1 0 0 /0 1 0 1 0 /0 1 0 1 0 /0 0 0 0 0 /0 0 0 0 0 0 /0 0 0 0 0 0 /1 1 1 1 0 0 /0 0 0 0 0 0 /0 0 1 1 0 0 /"
+		],
+		[
+			"cbUnshade",
+			"pzprv3/patchwork/6/6/8 # # . # 3 /# # # 0 # # /# # # . . - /. . . 1 # . /- . . . 1 - /. . 0 - # 1 /0 0 1 1 0 /0 0 1 1 0 /0 0 1 0 1 /0 0 1 0 1 /0 0 1 1 0 /0 0 1 1 0 /0 0 0 1 0 0 /0 0 0 1 1 1 /1 1 1 0 0 0 /0 0 0 1 1 1 /0 0 0 1 0 0 /"
+		],
+		[
+			"bkShadeNe",
+			"pzprv3/patchwork/6/6/8 # # + # 3 /# # # 0 # # /# # # + + - /+ + + 1 # + /- # + # 1 - /# # 0 - # 1 /0 0 1 1 0 /0 0 1 1 0 /0 0 1 0 1 /0 0 1 0 1 /0 0 1 1 0 /0 0 1 1 0 /0 0 0 1 0 0 /0 0 0 1 1 1 /1 1 1 0 0 1 /0 0 0 1 1 1 /0 0 0 1 0 0 /"
+		],
+		[
+			"bkNotSquare",
+			"pzprv3/patchwork/6/6/8 # # . . 3 /# # # 0 . . /# # # . . - /. . . 1 . . /- . . . 1 - /. . 0 - . 1 /0 0 1 0 0 /0 0 1 0 0 /0 0 1 0 0 /0 0 0 0 0 /0 0 0 0 0 /0 0 0 0 0 /0 0 0 0 0 0 /0 0 0 0 0 0 /1 1 1 0 0 0 /0 0 0 0 0 0 /0 0 0 0 0 0 /"
+		],
+		[
+			"bdDeadEnd",
+			"pzprv3/patchwork/6/6/8 # # + # 3 /# # # 0 # # /# # # + + - /+ + + 1 # + /- + + # 1 - /+ + 0 - # 1 /0 0 1 1 0 /0 0 1 1 0 /0 0 1 0 1 /0 0 1 0 1 /0 0 1 1 0 /0 0 1 1 0 /0 0 0 1 0 0 /0 0 0 1 1 1 /1 1 1 0 1 1 /0 0 0 1 1 1 /0 0 0 1 1 0 /"
+		],
+		[
+			null,
+			"pzprv3/patchwork/6/6/8 # # + # 3 /# # # 0 # # /# # # + + - /+ + + 1 # + /- + + # 1 - /+ + 0 - # 1 /0 0 1 1 0 /0 0 1 1 0 /0 0 1 0 1 /0 0 1 0 1 /0 0 1 1 0 /0 0 1 1 0 /0 0 0 1 0 0 /0 0 0 1 1 1 /1 1 1 0 0 1 /0 0 0 1 1 1 /0 0 0 1 0 0 /"
+		]
+	],
+	inputs: [
+		{
+			input: ["newboard,3,2", "editmode", "mouse,rightx2,3,1"],
+			result: "pzprv3/patchwork/2/3/. 5 . /. . . /0 0 /0 0 /0 0 0 /"
+		},
+		{
+			input: ["playmode", "mouse,left,1,1,1,3"],
+			result: "pzprv3/patchwork/2/3/# 5 . /# . . /0 0 /0 0 /0 0 0 /"
+		},
+		{
+			input: ["mouse,left,1.9,0,2.1,4", "mouse,right,5,2,5,1,5,3"],
+			result: "pzprv3/patchwork/2/3/# 5 . /# . . /1 0 /1 0 /0 0 -1 /"
+		},
+		{
+			input: ["mouse,leftx2,3,3", "mouse,left,4,3"],
+			result: "pzprv3/patchwork/2/3/# 5 . /# + . /1 0 /1 -1 /0 0 -1 /"
+		},
+		{
+			input: ["mouse,right,5,1", "mouse,left,5,2"],
+			result: "pzprv3/patchwork/2/3/# 5 + /# + . /1 0 /1 -1 /0 0 0 /"
+		}
+	]
+});