diff --git a/src/variety/nurimaze.js b/src/variety/nurimaze.js
index fee318fc1..c7f33f266 100644
--- a/src/variety/nurimaze.js
+++ b/src/variety/nurimaze.js
@@ -32,7 +32,33 @@
 		mouseinput_auto: function() {
 			if (this.puzzle.playmode) {
 				if (this.mousestart || this.mousemove) {
-					this.inputtile_nurimaze();
+					if (this.mousestart) {
+						this.inputData = null;
+						this.isLineDrag = false;
+						this.dragStartCell = this.getcell();
+					} else if (this.mousemove && !this.isLineDrag) {
+						var curCell = this.getcell();
+						if (
+							!curCell.isnull &&
+							!this.dragStartCell.isnull &&
+							curCell !== this.dragStartCell
+						) {
+							this.isLineDrag = true;
+							// ドラッグ開始セルを prevPos にセットして最初の線分も確実に描画する
+							this.prevPos = this.dragStartCell.getaddr();
+						}
+					}
+					if (this.isLineDrag) {
+						this.inputLine();
+					}
+					// isLineDrag が false の間は何もしない（mouseend でクリック判定する）
+				} else if (this.mouseend) {
+					if (!this.isLineDrag) {
+						// ドラッグなし＝クリックのみ → 部屋の補助記号を切り替え
+						this.mousestart = true;
+						this.inputtile_nurimaze();
+						this.mousestart = false;
+					}
 				}
 			} else if (this.puzzle.editmode) {
 				if (this.mousestart || this.mousemove) {
@@ -59,7 +85,8 @@
 					if (
 						clist[i].ques !== 0 ||
 						bd.startpos.equals(clist[i]) ||
-						bd.goalpos.equals(clist[i])
+						bd.goalpos.equals(clist[i]) ||
+						clist[i].lcnt > 0
 					) {
 						if (this.mousestart) {
 							this.inputData = cell.qsub !== 1 ? 2 : 0;
@@ -295,6 +322,32 @@
 	LineGraph: {
 		enabled: true
 	},
+	Border: {
+		posthook: {
+			line: function() {
+				// 補助線が引かれたら、両側のエリアを通路として確定する（壁かどうかに関わらず）
+				if (this.line > 0) {
+					for (var i = 0; i < this.sidecell.length; i++) {
+						var cell = this.sidecell[i];
+						if (!cell.isnull) {
+							var clist = cell.room.clist;
+							var changed = false;
+							for (var j = 0; j < clist.length; j++) {
+								if (clist[j].isShade() || clist[j].qsub !== 1) {
+									clist[j].clrShade();
+									clist[j].setQsub(1);
+									changed = true;
+								}
+							}
+							if (changed) {
+								clist.draw();
+							}
+						}
+					}
+				}
+			}
+		}
+	},
 	BorderList: {
 		subclear: function() {
 			this.propclear(["sub", "info", "ans"], true);
@@ -308,6 +361,7 @@
 		bgcellcolor_func: "qsub1",
 		errbcolor2: "rgb(192, 192, 255)",
 		bbcolor: "rgb(96, 96, 96)",
+		linecolor: "rgb(160, 160, 160)",
 
 		irowake: true,
 
@@ -316,6 +370,8 @@
 			this.drawShadedCells();
 			this.drawGrid();
 
+			this.drawLines();
+
 			this.drawQuesMarks();
 			this.drawStartGoal();
 
@@ -326,8 +382,6 @@
 			this.drawBoxBorders(true);
 
 			this.drawTarget();
-
-			this.drawLines();
 		},
 
 		drawQuesMarks: function() {
diff --git a/test/script/nurimaze.js b/test/script/nurimaze.js
index 131c981af..5e503d048 100644
--- a/test/script/nurimaze.js
+++ b/test/script/nurimaze.js
@@ -112,32 +112,32 @@ ui.debug.addDebugData("nurimaze", {
 		{
 			input: ["mouse,left, 1,3, 7,3"],
 			result:
-				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /+ + + + /+ + + + /. . . . /"
+				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /+ + + + /+ + + + /. . . . /0 0 0 /1 1 1 /0 0 0 /0 0 0 0 /0 0 0 0 /"
 		},
 		{
 			input: ["mouse,left, 7,3, 1,3"],
 			result:
-				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /+ # # # /+ # # # /. . . . /"
+				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /+ + + + /+ + + + /. . . . /"
 		},
 		{
 			input: ["mouse,left, 1,3, 7,3"],
 			result:
-				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /. . . . /. . . . /. . . . /"
+				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /+ + + + /+ + + + /. . . . /0 0 0 /1 1 1 /0 0 0 /0 0 0 0 /0 0 0 0 /"
 		},
 		{
 			input: ["mouse,left, 1,3, 7,3", "mouse,right, 7,3, 1,3"],
 			result:
-				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /. . . . /. . . . /. . . . /"
+				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /+ + + + /+ + + + /. . . . /0 0 0 /1 1 1 /0 0 0 /0 0 0 0 /0 0 0 0 /"
 		},
 		{
 			input: ["mouse,right, 1,5, 7,5"],
 			result:
-				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /. . . . /. . . . /+ + + + /"
+				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /+ + + + /+ + + + /+ + + + /0 0 0 /1 1 1 /1 1 1 /0 0 0 0 /0 0 0 0 /"
 		},
 		{
 			input: ["mouse,left, 1,5, 7,5"],
 			result:
-				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /. . . . /. . . . /# # # + /"
+				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . . . /. . . g /+ + + + /+ + + + /+ + + + /0 0 0 /1 1 1 /0 0 0 /0 0 0 0 /0 0 0 0 /"
 		},
 		{
 			input: [
@@ -153,7 +153,7 @@ ui.debug.addDebugData("nurimaze", {
 		{
 			input: ["mouse,left, 7,3, 1,3, 1,5, 7,5"],
 			result:
-				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . o . /. t . g /. # . # /. # . # /# . # . /"
+				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . o . /. t . g /+ + + + /+ + + + /+ + + + /0 0 0 /1 1 1 /1 1 1 /0 0 0 0 /1 0 0 0 /"
 		},
 		{
 			input: ["mouse,right, 7,3, 1,3, 1,5, 7,5"],
@@ -164,7 +164,7 @@ ui.debug.addDebugData("nurimaze", {
 		{
 			input: ["mouse,left, 7,3, 1,3, 1,5, 7,5"],
 			result:
-				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . o . /. t . g /. . . . /. . . . /. . . . /"
+				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . o . /. t . g /+ + + + /+ + + + /+ + + + /"
 		},
 		{
 			input: ["ansclear", "playmode,line"]
@@ -172,12 +172,12 @@ ui.debug.addDebugData("nurimaze", {
 		{
 			input: ["mouse,left, 7,3, 1,3, 1,5, 7,5"],
 			result:
-				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . o . /. t . g /. . . . /. . . . /. . . . /0 0 0 /1 1 1 /1 1 1 /0 0 0 0 /1 0 0 0 /"
+				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . o . /. t . g /+ + + + /+ + + + /+ + + + /0 0 0 /1 1 1 /1 1 1 /0 0 0 0 /1 0 0 0 /"
 		},
 		{
 			input: ["mouse,left, 3,3, 1,3, 1,5, 3,5"],
 			result:
-				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . o . /. t . g /. . . . /. . . . /. . . . /0 0 0 /0 1 1 /0 1 1 /0 0 0 0 /0 0 0 0 /"
+				"pzprv3/nurimaze/3/4/8/0 1 2 3 /0 1 2 3 /4 5 6 7 /s . . . /. . o . /. t . g /+ + + + /+ + + + /+ + + + /0 0 0 /0 1 1 /0 1 1 /0 0 0 0 /0 0 0 0 /"
 		},
 		{
 			input: ["subclear"],