diff --git a/ykoiso/src/A055_EscapeGame.java b/ykoiso/src/A055_EscapeGame.java
new file mode 100644
index 0000000000000000000000000000000000000000..f3fa79f7383b2eebeb927d1cdbe45411462f5e3b
--- /dev/null
+++ b/ykoiso/src/A055_EscapeGame.java
@@ -0,0 +1,119 @@
+import java.util.Map;
+import java.util.Scanner;
+
+public class A055_EscapeGame {
+    // マップ記号のenum、Mapのほうが良かったかも
+    public enum STR {
+        START("S"), WALL("#"), ROAD(".");
+
+        private String chr;
+
+        STR(String chr) {
+            this.chr = chr;
+        }
+
+        public String getChr() {
+            return chr;
+        }
+    }
+
+    public static void main(String[] args) {
+        Scanner scan = new Scanner(System.in);
+        // 定数の読み込み
+        final int HEIGHT = scan.nextInt();
+        final int WIDTH = scan.nextInt();
+        final String[][] MAP = new String[HEIGHT][WIDTH];
+        int startH = 0;
+        int startW = 0;
+        // マップの生成
+        // 1列分読み込んでから1文字に分けて格納
+        for (int H = 0; H < HEIGHT; H++) {
+            String str = scan.next();
+            for (int W = 0; W < WIDTH; W++) {
+                MAP[H][W] = str.substring(W);
+                if (MAP[H][W] == STR.START.getChr()) {
+                    startH = H;
+                    startW = W;
+                }
+            }
+        }
+        // マップ探索クラスの生成
+        A055_EscapeGame cls = new A055_EscapeGame();
+        SearchMap searchMap = cls.new SearchMap(MAP, startH, startW, HEIGHT, WIDTH);
+        // 探索開始
+        searchMap.search();
+        scan.close();
+    }
+
+    class SearchMap {
+        // マップ
+        private String[][] map;
+        // スタート座標
+        private int startH;
+        private int startW;
+        // 探索したかの判定
+        private boolean[][] isSearch;
+        // マップの縦横
+        private int height;
+        private int width;
+        // 脱出可能かの判定
+        private boolean isEscape = false;
+
+        // テスト用
+        public boolean isEscape() {
+            return isEscape;
+        }
+
+        // コンストラクタ
+        SearchMap(final String[][] map, final int startH, final int startW, final int height,
+                final int width) {
+            this.map = map;
+            this.startH = startH;
+            this.startW = startW;
+            this.height = height;
+            this.width = width;
+            isSearch = new boolean[height][width];
+        }
+
+        // 探索関数
+        public void search() {
+            searchAdjacent(startH, startW);
+            System.out.println(makeAnswer());
+        }
+
+        // 答えの出力
+        public String makeAnswer() {
+            if (isEscape == true) {
+                return "YES";
+            } else {
+                return "NO";
+            }
+        }
+
+        // 目標座標の縦横の探索
+        public void searchAdjacent(final int height, final int width) {
+            // 外壁まで来てたら探索終了
+            if (height == 0 || width == 0 || height == this.height - 1 || width == this.width - 1) {
+                isEscape = true;
+            }
+            // 探索中なら探索を進める
+            if (isEscape == false) {
+                checkRoad(height - 1, width);
+                checkRoad(height + 1, width);
+                checkRoad(height, width - 1);
+                checkRoad(height, width + 1);
+            }
+        }
+
+        // 目的座標が移動できるかの判定
+        // 移動出来たら再帰的に探索を進める
+        public void checkRoad(final int height, final int width) {
+            // 目的座標が道かつ未探索なら探索済みにして再帰
+            STR str = STR.valueOf(map[height][width]);
+            if (str == STR.ROAD && isSearch[height][width] == false) {
+                isSearch[height][width] = true;
+                searchAdjacent(height, width);
+            }
+        }
+    }
+}
diff --git a/ykoiso/test/A055_EscapeGameTest.java b/ykoiso/test/A055_EscapeGameTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..0a1fd3b0166a9280814d4cb20eff43092a14ca40
--- /dev/null
+++ b/ykoiso/test/A055_EscapeGameTest.java
@@ -0,0 +1,72 @@
+import static org.junit.Assert.assertThat;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.*;
+
+public class A055_EscapeGameTest {
+    A055_EscapeGame cls = new A055_EscapeGame();
+    A055_EscapeGame.SearchMap sut;
+    int startH;
+    int startW;
+
+    @Test
+    public void 道があると判断できる() {
+        String[][] map = {{"#", ".", "#"}, {"#", "S", "#"}, {"#", "#", "#"}};
+        startH = 1;
+        startW = 1;
+        sut = cls.new SearchMap(map, startH, startW, 3, 3);
+        sut.searchAdjacent(startH, startW);
+        boolean actual = sut.isEscape();
+        assertThat(actual, is(true));
+    }
+
+    @Test
+    public void 道がないと判断できる() {
+        String[][] map = {{"#", "#", "#"}, {"#", "S", "#"}, {"#", "#", "#"}};
+        startH = 1;
+        startW = 1;
+        sut = cls.new SearchMap(map, startH, startW, 3, 3);
+        sut.searchAdjacent(startH, startW);
+        boolean actual = sut.isEscape();
+        assertThat(actual, is(false));
+    }
+
+    @Test
+    public void 縦横5マスでも再帰的に探索できる() {
+        String[][] map = {{"#", "#", "#", "#", "#"}, {"#", "#", "#", "#", "#"},
+                {"#", "#", "S", "#", "#"}, {"#", "#", ".", ".", "#"}, {"#", "#", "#", ".", "#"}};
+        startH = 3;
+        startW = 3;
+        sut = cls.new SearchMap(map, startH, startW, 5, 5);
+        sut.searchAdjacent(startH, startW);
+        boolean actual = sut.isEscape();
+        assertThat(actual, is(true));
+    }
+
+    // makeAnswerテスト
+    @Test
+    public void 道があるときYESを返す() {
+        String[][] map = {{"#", "#", "#"}, {"#", "S", "#"}, {"#", ".", "#"}};
+        startH = 1;
+        startW = 1;
+        sut = cls.new SearchMap(map, startH, startW, 3, 3);
+        sut.searchAdjacent(startH, startW);
+        String actual = sut.makeAnswer();
+        String expected = "YES";
+        assertThat(actual, is(expected));
+    }
+
+    @Test
+    public void 道がないときNOを返す() {
+        String[][] map = {{"#", "#", "#"}, {"#", "S", "#"}, {"#", "#", "#"}};
+        startH = 1;
+        startW = 1;
+        sut = cls.new SearchMap(map, startH, startW, 3, 3);
+        String actual = sut.makeAnswer();
+        String expected = "NO";
+        assertThat(actual, is(expected));
+    }
+}