diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 8829598c0..245c09a0c 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -284,6 +284,9 @@ importers:
       '@vercel/analytics':
         specifier: ^2.0.1
         version: 2.0.1(react@19.2.4)
+      '@xterm/addon-canvas':
+        specifier: ^0.7.0
+        version: 0.7.0(@xterm/xterm@5.5.0)
       '@xterm/addon-fit':
         specifier: ^0.10.0
         version: 0.10.0(@xterm/xterm@5.5.0)
@@ -1769,6 +1772,11 @@ packages:
     resolution: {integrity: sha512-A9gOqLdi6cV4ibazAjcQufGj0B1y/vDqYrcuP6d/6x8P27gRS8643Dj9o1dEKtB6O7fwxb2FgBmJS2mX7gpvdw==}
     engines: {node: '>=14.6'}
 
+  '@xterm/addon-canvas@0.7.0':
+    resolution: {integrity: sha512-LF5LYcfvefJuJ7QotNRdRSPc9YASAVDeoT5uyXS/nZshZXjYplGXRECBGiznwvhNL2I8bq1Lf5MzRwstsYQ2Iw==}
+    peerDependencies:
+      '@xterm/xterm': ^5.0.0
+
   '@xterm/addon-fit@0.10.0':
     resolution: {integrity: sha512-UFYkDm4HUahf2lnEyHvio51TNGiLK66mqP2JoATy7hRZeXaGMRDr00JiSF7m63vR5WKATF605yEggJKsw0JpMQ==}
     peerDependencies:
@@ -6018,6 +6026,10 @@ snapshots:
 
   '@xmldom/xmldom@0.9.10': {}
 
+  '@xterm/addon-canvas@0.7.0(@xterm/xterm@5.5.0)':
+    dependencies:
+      '@xterm/xterm': 5.5.0
+
   '@xterm/addon-fit@0.10.0(@xterm/xterm@5.5.0)':
     dependencies:
       '@xterm/xterm': 5.5.0
diff --git a/ui/package.json b/ui/package.json
index 582ac5a99..132d225c1 100644
--- a/ui/package.json
+++ b/ui/package.json
@@ -12,6 +12,7 @@
   },
   "dependencies": {
     "@vercel/analytics": "^2.0.1",
+    "@xterm/addon-canvas": "^0.7.0",
     "@xterm/addon-fit": "^0.10.0",
     "@xterm/addon-web-links": "^0.11.0",
     "@xterm/addon-webgl": "^0.18.0",
diff --git a/ui/src/components/workspace/Terminal.tsx b/ui/src/components/workspace/Terminal.tsx
index 6204e32d1..41434232b 100644
--- a/ui/src/components/workspace/Terminal.tsx
+++ b/ui/src/components/workspace/Terminal.tsx
@@ -1,9 +1,9 @@
 import { lazy, Suspense, useEffect, useRef, useState } from 'react';
 import type { ReactElement } from 'react';
 
+import { CanvasAddon } from '@xterm/addon-canvas';
 import { FitAddon } from '@xterm/addon-fit';
 import { WebLinksAddon } from '@xterm/addon-web-links';
-import { WebglAddon } from '@xterm/addon-webgl';
 import { Terminal as Xterm } from '@xterm/xterm';
 import '@xterm/xterm/css/xterm.css';
 
@@ -112,7 +112,7 @@ export function TerminalView(props: TerminalViewProps): ReactElement {
     const term = new Xterm({
       theme: darkTheme,
       fontFamily:
-        'ui-monospace, "SF Mono", Menlo, Monaco, "Cascadia Mono", "DejaVu Sans Mono", monospace',
+        'ui-monospace, "SF Mono", Menlo, Monaco, "Cascadia Mono", "DejaVu Sans Mono", "Noto Sans Mono CJK JP", "Noto Sans CJK JP", monospace',
       fontSize: 13,
       lineHeight: 1.2,
       cursorBlink: true,
@@ -127,13 +127,20 @@ export function TerminalView(props: TerminalViewProps): ReactElement {
     term.loadAddon(new WebLinksAddon());
     term.open(container);
 
-    let webgl: WebglAddon | null = null;
+    // Canvas renderer (not WebGL). The WebGL glyph atlas renders any styled
+    // CJK cell it can't rasterize — notably italic Japanese, since Noto Sans
+    // Mono CJK JP has no italic face — as a solid black box. Canvas rasterizes
+    // each cell via 2D fillText, which falls back through the browser font
+    // stack and synthesizes obliques, so bold/italic Japanese renders
+    // correctly. It's far faster than the DOM renderer (which made input echo
+    // sluggish in heavy TUIs like the agent CLIs) while avoiding WebGL's
+    // missing-glyph boxes.
+    let canvas: CanvasAddon | null = null;
     try {
-      webgl = new WebglAddon();
-      webgl.onContextLoss(() => webgl?.dispose());
-      term.loadAddon(webgl);
+      canvas = new CanvasAddon();
+      term.loadAddon(canvas);
     } catch {
-      webgl = null;
+      canvas = null;
     }
 
     safeFit(fit);
@@ -257,7 +264,7 @@ export function TerminalView(props: TerminalViewProps): ReactElement {
       } catch {
         // ignore
       }
-      webgl?.dispose();
+      canvas?.dispose();
       term.dispose();
     };
   }, [wsId, sessionId, wsUrl]);