diff --git a/.zed/tasks.json b/.zed/tasks.json
index 34420e6..4868825 100644
--- a/.zed/tasks.json
+++ b/.zed/tasks.json
@@ -1,10 +1,9 @@
+// Static tasks configuration.
+//
+// Example:
 [
   {
     "label": "Test",
     "command": "deno test"
-  },
-  {
-    "label": "Test - Watch",
-    "command": "deno test --watch"
   }
 ]
diff --git a/deno.json b/deno.json
index ffdf2b3..14c2394 100644
--- a/deno.json
+++ b/deno.json
@@ -1,9 +1,8 @@
 {
   "name": "@textplace/core",
-  "version": "0.4.1",
+  "version": "0.3.0",
   "exports": "./mod.ts",
   "imports": {
-    "@deno/dnt": "jsr:@deno/dnt@^0.41.3",
-    "@std/cli": "jsr:@std/cli@^1.0.11"
+    "@deno/dnt": "jsr:@deno/dnt@^0.41.3"
   }
 }
diff --git a/deno.lock b/deno.lock
index afae4c4..491b9f0 100644
--- a/deno.lock
+++ b/deno.lock
@@ -7,7 +7,6 @@
     "jsr:@std/assert@0.223": "0.223.0",
     "jsr:@std/assert@0.226": "0.226.0",
     "jsr:@std/bytes@0.223": "0.223.0",
-    "jsr:@std/cli@^1.0.11": "1.0.11",
     "jsr:@std/fmt@0.223": "0.223.0",
     "jsr:@std/fmt@1": "1.0.3",
     "jsr:@std/fs@0.223": "0.223.0",
@@ -55,9 +54,6 @@
     "@std/bytes@0.223.0": {
       "integrity": "84b75052cd8680942c397c2631318772b295019098f40aac5c36cead4cba51a8"
     },
-    "@std/cli@1.0.11": {
-      "integrity": "ec219619fdcd31bcf0d8e53bee1e2706ec9a02f70255365a094f69755dadd340"
-    },
     "@std/fmt@0.223.0": {
       "integrity": "6deb37794127dfc7d7bded2586b9fc6f5d50e62a8134846608baf71ffc1a5208"
     },
@@ -155,8 +151,7 @@
   },
   "workspace": {
     "dependencies": [
-      "jsr:@deno/dnt@~0.41.3",
-      "jsr:@std/cli@^1.0.11"
+      "jsr:@deno/dnt@~0.41.3"
     ]
   }
 }
diff --git a/logic/board.ts b/logic/board.ts
index 0436cdc..9dcb312 100644
--- a/logic/board.ts
+++ b/logic/board.ts
@@ -106,9 +106,9 @@ export function renderFullBoard(data: BoardData): FullBoard {
   return {
     w: lineLength,
     h: totalLineCount,
-    ch: chLines.flat(),
-    color: colorLines.flat(),
-    bg_color: bgColorLines.flat(),
-    width: widthLines.flat(),
+    ch: ([] as string[]).concat(...chLines).flat(),
+    color: ([] as string[]).concat(...colorLines).flat(),
+    bg_color: ([] as string[]).concat(...bgColorLines).flat(),
+    width: ([] as number[]).concat(...widthLines).flat(),
   };
 }
diff --git a/logic/character.ts b/logic/character.ts
index 2d58dac..d1b9f69 100644
--- a/logic/character.ts
+++ b/logic/character.ts
@@ -1,6 +1,7 @@
-import { unicodeWidth } from "@std/cli/unicode-width";
-
 const segmenter = new Intl.Segmenter("en", { granularity: "grapheme" });
+const cjkRegex =
+  /[\p{Unified_Ideograph}\u30A0-\u30FF\u3040-\u309F\u31F0-\u31FF]/u;
+const printableASCIIRegex = /^[\x20-\x7E]$/;
 
 export function getCharacterWidth(ch: string): number {
   const segments = [...segmenter.segment(ch)];
@@ -10,6 +11,11 @@ export function getCharacterWidth(ch: string): number {
     );
   }
 
-  // TODO: Properly fix this.
-  return Math.min(unicodeWidth(ch), 2);
+  const matchesASCII = ch.match(printableASCIIRegex);
+  const matchesCJK = ch.match(cjkRegex);
+
+  if (!matchesASCII && !matchesCJK) throw new Error(`Invalid character: ${ch}`);
+
+  // TODO: Support Emojis.
+  return matchesCJK ? 2 : 1;
 }
diff --git a/logic/section.ts b/logic/section.ts
index c3f976c..d935dc3 100644
--- a/logic/section.ts
+++ b/logic/section.ts
@@ -16,17 +16,17 @@ export function createSection(
   const offsetX = sx * boardConfig.sectionWidth;
   const offsetY = sy * boardConfig.sectionHeight;
 
-  const ch: string[][] = Array(boardConfig.sectionHeight).fill([]).map(() =>
-    Array(boardConfig.sectionWidth).fill(boardConfig.defaultCh)
+  const ch: string[][] = Array(boardConfig.sectionHeight).fill(
+    Array(boardConfig.sectionWidth).fill(boardConfig.defaultCh),
   );
-  const color: string[][] = Array(boardConfig.sectionHeight).fill([]).map(() =>
-    Array(boardConfig.sectionWidth).fill(boardConfig.defaultColor)
+  const color: string[][] = Array(boardConfig.sectionHeight).fill(
+    Array(boardConfig.sectionWidth).fill(boardConfig.defaultColor),
   );
-  const bgColor: string[][] = Array(boardConfig.sectionHeight).fill([]).map(
-    () => Array(boardConfig.sectionWidth).fill(boardConfig.defaultBgColor),
+  const bgColor: string[][] = Array(boardConfig.sectionHeight).fill(
+    Array(boardConfig.sectionWidth).fill(boardConfig.defaultBgColor),
   );
-  const width: number[][] = Array(boardConfig.sectionHeight).fill([]).map(() =>
-    Array(boardConfig.sectionWidth).fill(boardConfig.defaultWidth)
+  const width: number[][] = Array(boardConfig.sectionHeight).fill(
+    Array(boardConfig.sectionWidth).fill(boardConfig.defaultWidth),
   );
 
   return { offsetX, offsetY, ch, color, bgColor, width };
@@ -44,7 +44,7 @@ export function applyChange(change: BoardChange, section: SectionData) {
 
   if (change.ch) {
     const chWidth = getCharacterWidth(change.ch);
-    const xCharacterOffset = xInSection % chWidth;
+    const xCharacterOffset = xInSection % 2;
     const offsetAdjustedXInSection = xInSection - xCharacterOffset;
     section.ch[yInSection][offsetAdjustedXInSection] = change.ch;
     section.width[yInSection][offsetAdjustedXInSection] = chWidth;
diff --git a/tests/board.test.ts b/tests/board.test.ts
index 735bf32..ecedc47 100644
--- a/tests/board.test.ts
+++ b/tests/board.test.ts
@@ -51,12 +51,11 @@ Deno.test("board", async (t) => {
     applyChangeOnBoard({ x: 4, y: 0, ch: "B" }, board);
     applyChangeOnBoard({ x: 0, y: 3, ch: "C" }, board);
     applyChangeOnBoard({ x: 4, y: 3, ch: "D" }, board);
-    applyChangeOnBoard({ x: 5, y: 3, ch: "E" }, board);
 
     assertEquals(board.sections[0][0].ch[0][0], "A");
     assertEquals(board.sections[0][1].ch[0][0], "B");
     assertEquals(board.sections[1][0].ch[0][0], "C");
-    assertEquals(board.sections[1][1].ch[0], ["D", "E", " ", " "]);
+    assertEquals(board.sections[1][1].ch[0][0], "D");
 
     applyChangeOnBoard({ x: 0, y: 1, ch: "你" }, board);
     applyChangeOnBoard({ x: 4, y: 2, ch: "好" }, board);
@@ -66,10 +65,7 @@ Deno.test("board", async (t) => {
     assertEquals(board.sections[0][0].ch[1][0], "你");
     assertEquals(board.sections[0][1].ch[2][0], "好");
     assertEquals(board.sections[1][0].ch[1][0], "嗎");
-    assertEquals(board.sections[1][1].ch[1], ["嘛", " ", " ", " "]);
-
-    applyChangeOnBoard({ x: 5, y: 4, ch: "啊" }, board);
-    assertEquals(board.sections[1][1].ch[1], ["啊", " ", " ", " "]);
+    assertEquals(board.sections[1][1].ch[2][0], "嘛");
   });
 
   await t.step("getSectionOnBoard: existing section", () => {
@@ -78,10 +74,10 @@ Deno.test("board", async (t) => {
     const section = getSectionOnBoard({ sx: 1, sy: 1 }, board, {
       readOnly: true,
     });
-    assertEquals(section.ch[0], ["D", "E", " ", " "]);
+    assertEquals(section.ch[0][0], "嘛");
     assertEquals(section.color[0][0], "F");
     assertEquals(section.bgColor[0][0], "0");
-    assertEquals(section.width[0], [1, 1, 1, 1]);
+    assertEquals(section.width[0][0], 2);
   });
 
   await t.step("getSectionOnBoard: non-existing row", () => {
@@ -118,7 +114,7 @@ Deno.test("board", async (t) => {
   await t.step("on-demand creation: only changed sections are saved", () => {
     assert(board);
 
-    assertEquals(board.sections[2], undefined);
-    assertEquals(board.sections[0][2], undefined);
+    assertEquals(board.sections.length, 2);
+    assertEquals(board.sections[0].length, 2);
   });
 });
diff --git a/tests/character.test.ts b/tests/character.test.ts
index c8e3a65..886d7ad 100644
--- a/tests/character.test.ts
+++ b/tests/character.test.ts
@@ -26,18 +26,14 @@ Deno.test("getCharacterWidth CJK", () => {
   assertEquals(getCharacterWidth("グ"), 2);
   assertEquals(getCharacterWidth("ソ"), 2);
 
-  assertEquals(getCharacterWidth("？"), 2);
-  assertEquals(getCharacterWidth("！"), 2);
+  assertThrows(() => getCharacterWidth("？"));
+  assertThrows(() => getCharacterWidth("！"));
   assertThrows(() => getCharacterWidth("你好"));
   assertThrows(() => getCharacterWidth("ヨスガノ"));
 });
 
-Deno.test("getCharacterWidth Emoji", () => {
-  assertEquals(getCharacterWidth("👋"), 2);
-  assertEquals(getCharacterWidth("🌲️"), 2);
-  assertEquals(getCharacterWidth("👨‍👩‍👧‍👦"), 2);
-});
-
 Deno.test("getCharacterWidth previously faulty cases", () => {
   assertEquals(getCharacterWidth("𤲶"), 2);
+
+  assertThrows(() => getCharacterWidth("𤲶"[0]));
 });
diff --git a/tests/checkFullBoard.ts b/tests/checkFullBoard.ts
index 9484c40..9984249 100644
--- a/tests/checkFullBoard.ts
+++ b/tests/checkFullBoard.ts
@@ -47,11 +47,6 @@ export function checkFullBoard(board: FullBoard) {
       console.error("width:   ", widthLine);
     };
 
-    if (typeof cCh !== "string") {
-      printSituation();
-      throw new Error("cCh is not string");
-    }
-
     if (!isValidColor(cCo) || !isValidColor(cBg)) {
       printSituation();
       throw new Error("cCo or cBg is not valid");
diff --git a/tests/section.test.ts b/tests/section.test.ts
index a70da5b..8a5a139 100644
--- a/tests/section.test.ts
+++ b/tests/section.test.ts
@@ -90,33 +90,27 @@ Deno.test("section", async (t) => {
     assert(section);
 
     applyChange({ x: 0, y: 0, ch: "t" }, section);
-    assertEquals(section.ch[0], ["t", " ", " ", " "]);
-    assertEquals(section.ch[1], [" ", " ", " ", " "]);
-    assertEquals(section.width[0], [1, 1, 1, 1]);
-  });
-
-  await t.step("applyChange 1-width at odd position", () => {
-    assert(section);
-
-    applyChange({ x: 1, y: 0, ch: "t" }, section);
-    assertEquals(section.ch[0], ["t", "t", " ", " "]);
-    assertEquals(section.width[0], [1, 1, 1, 1]);
+    assertEquals(section.ch[0][0], "t");
+    assertEquals(section.ch[0][1], " ");
+    assertEquals(section.width[0][0], 1);
   });
 
   await t.step("applyChange 2-width at a correct position", () => {
     assert(section);
 
     applyChange({ x: 0, y: 0, ch: "あ" }, section);
-    assertEquals(section.ch[0], ["あ", "t", " ", " "]);
-    assertEquals(section.width[0], [2, 1, 1, 1]);
+    assertEquals(section.ch[0][0], "あ");
+    assertEquals(section.ch[0][1], " ");
+    assertEquals(section.width[0][0], 2);
   });
 
   await t.step("applyChange 2-width at an alternate position", () => {
     assert(section);
 
     applyChange({ x: 1, y: 0, ch: "あ" }, section);
-    assertEquals(section.ch[0], ["あ", "t", " ", " "]);
-    assertEquals(section.width[0], [2, 1, 1, 1]);
+    assertEquals(section.ch[0][0], "あ");
+    assertEquals(section.ch[0][1], " ");
+    assertEquals(section.width[0][0], 2);
   });
 
   await t.step("applyChange incorrect section", () => {