Japanese input on Omarchy 4 with fcitx5-mozc

Omarchy does most of the work for you already, and that is the part people miss. fcitx5 is not an optional extra. It has been in the base package list since the 3.x releases, and since 4.0.0 it runs as a supervised systemd user service, because the whole CapsLock compose system depends on it. The fonts are there too: noto-fonts-cjk is in the base package list, so Japanese renders before you type any of it.

What is missing is the engine and one line in a config file. The official manual covers this in one paragraph of the Keyboard, Mouse, Trackpad chapter, which tells you to install fcitx5-mozc and fcitx5-configtool and stops there. This page fills in the rest.

Checked against v4.0.4 (2026-09-15).

The fix

1. Install the engine and the config tool.

omarchy pkg add fcitx5-mozc fcitx5-configtool

2. Restart the fcitx5 service so it discovers the new engine. Omarchy 4 supervises fcitx5 with a systemd user unit, so do not just pkill it.

omarchy restart xcompose

That wrapper stops omarchy-fcitx5.service, kills any stray fcitx5 process, and starts the unit again. The stray-kill matters: a second fcitx5 that finds the D-Bus name already taken exits cleanly, so if a copy started outside the unit is still alive, systemd will report a successful restart while the old process keeps serving.

3. Add Mozc to your input method group.

fcitx5-configtool

In the left pane, add Mozc to the current group. Keep a keyboard layout entry (Keyboard - English (US), or Keyboard - Japanese on a JIS board) as the first entry, so plain Latin typing stays the default and Mozc is what you switch into.

4. Apply, close, and log out and back in if any already-running app ignores the new engine. Toggle with Ctrl + Space, which is fcitx5’s stock trigger key. On a JIS board, Zenkaku_Hankaku is in the same default trigger list.

Verify it worked

systemctl --user is-active omarchy-fcitx5.service
fcitx5-remote -n

The first should print active. The second prints the current input method name; press Ctrl + Space and run it again, and it should flip between your keyboard layout and mozc.

Then open a terminal and type nihongo. You should get a hiragana preedit and a candidate list, and space should convert it to 日本語.

If you want to check the group programmatically, ask fcitx5 over D-Bus:

busctl --user --json=short call org.fcitx.Fcitx5 /controller \
  org.fcitx.Fcitx.Controller1 InputMethodGroupInfo s "$(fcitx5-remote -q)"

mozc should appear in the returned list.

Why it happens

Omarchy sets INPUT_METHOD, QT_IM_MODULE, XMODIFIERS and SDL_IM_MODULE to fcitx in /usr/lib/environment.d/10-omarchy-fcitx.conf. It does not set GTK_IM_MODULE. On Wayland, GTK uses the text-input protocol instead of an im-module, and an older migration (the one that moved logins to UWSM, still shipped in 3.8.4) strips GTK_IM_MODULE=fcitx out of ~/.config/environment.d/fcitx.conf. If you find a guide or a plugin README telling you to add it back, skip that line. It is a leftover from X11 setups, and Omarchy’s own migration removes it.

This is also why nothing about the framework needs installing. The only thing omarchy pkg add fcitx5-mozc changes is which engines fcitx5 can offer.

Known pitfalls on 4.0.x

fcitx5-configtool will not appear in the launcher. Omarchy hides it on purpose: fcitx5-configtool, org.fcitx.Fcitx5 and the other fcitx desktop entries are all listed in default/omarchy/launcher.hides. Run it from a terminal. akitaonrails flagged exactly this on PR #9634 as a few confused minutes of hunting.

Chromium may ignore the IME. Whether Chromium-based browsers need --enable-wayland-ime to take the Wayland text-input path is contested. akitaonrails reported on PR #9634 that on 4.0.4 every terminal and GTK and Qt app accepted Japanese after setup while the browser did not until the flag was set, and opened PR #12139 to ship it. PR #11719 argues that current Chromium enables text-input-v3 by default and the flag is redundant, and issue #7559 lists only the stock ozone flags for Chromium and reports conversion working. Omarchy 4.0.4 does not ship the flag. If your browser drops the IME, add it yourself:

echo '--enable-wayland-ime' >> ~/.config/chromium-flags.conf

Restart the browser afterwards. PR #12139 also carries a migration for existing installs, because omarchy-install-browser copies the flags file once, at install time. It was open on 2026-09-16.

The candidate window is misplaced in native Wayland Chromium and Electron apps. Issue #7559 reports the popup not following the caret in Chromium and Obsidian, while the same apps behave under XWayland. Input and conversion still work. Open as of this writing.

The candidate popup is invisible in true fullscreen. Issue #11303 covers a native Wayland terminal put into Hyprland’s internal fullscreen with SUPER + F. Composition and commit still work, but you cannot see the candidate list. The issue points at Omarchy’s SUPER + CTRL + F tiled fullscreen binding, which avoids the failing internal fullscreen state, as the workaround.

Do not expect a Shift-key toggle. Omarchy’s default kb_options is compose:caps,shift:both_capslock_cancel. Issue #7440 traced why fcitx5’s modifier-only Shift trigger never fires under it: the Shift release arrives with a Caps_Lock keysym, so fcitx5’s release matching fails. Stick with Ctrl + Space or, on a JIS board, the Zenkaku_Hankaku key.

Super + Space is not available as a switch key. Hyprland grabs it for the Omarchy menu, and Super + Shift + Space toggles the top bar. Those are fcitx5’s usual group-enumerate defaults, so they never reach fcitx5.

Do not switch layouts through Hyprland once fcitx5 is running. Issue #9552 describes the trap: a grp: xkb toggle or the bar widget changes the label and hyprctl devices agrees, but typed characters stay in the old layout in most apps. The issue’s own workaround is disabling omarchy-fcitx5.service, which also takes Mozc and the compose sequences with it. For a Japanese setup, keep the layouts you need as keyboard entries in the fcitx5 group next to Mozc and switch there.

The Omarchy menu search field does not accept composed text. Issue #11682 reports the Quickshell menu collecting raw key events instead of going through Qt’s input method, so CJK preedit never reaches it. Filed against Hangul, and the same code path applies to Mozc.

Dictation is a separate problem. Issue #10050 reports Voxtype’s default type mode corrupting longer Japanese text through wtype.

JIS keyboards and the resize bindings. Issue #10452 points out that the window resize shortcuts are bound to physical keycodes (code:20, code:21) but labelled MINUS and EQUAL, which do not line up on a JIS board.

If that did not work

If fcitx5-remote -n returns nothing or errors, fcitx5 is not running for your session. Check systemctl --user status omarchy-fcitx5.service. The unit has ConditionEnvironment=WAYLAND_DISPLAY, so it deliberately does not start over SSH.

If the journal shows the service restarting over and over, you probably have a leftover autostart entry launching fcitx5 under its own name. Issue #7461 documents a machine that reached over 11,000 restarts this way. Remove the stray .desktop file from ~/.config/autostart/ and restart the unit.

If Mozc shows up in the config tool but disappears after a reboot, you probably edited ~/.config/fcitx5/profile by hand while fcitx5 was running. fcitx5 rewrites that file from its live state on exit, which is why PR #9634 registers the engine over D-Bus rather than by editing the file.

What is coming

PR #9634 by komagata adds Setup > Input Method > Mozc (Japanese) to the Omarchy menu, backed by a small omarchy-setup-input-mozc script that installs the package, restarts fcitx5, waits for it to answer, and appends mozc to the current group over D-Bus. It also rewrites the manual paragraph to point at the menu. It was open on 2026-09-16. A Korean sibling, PR #11719, takes the same shape, and PR #12142 would make the candidate window follow your Omarchy theme. None of these are merged, so treat the manual steps above as the current path.

For a bar indicator, two third-party Quickshell plugins exist. komagata/omarchy-input-method builds its list from the active fcitx5 group, so it covers Mozc, Rime and Hangul alike. Praveensenpai/omarchy-japanese-ime is Japanese-specific and shows あ or a keyboard glyph. Both are MIT licensed; komagata’s was last pushed on 2026-09-06 and Praveensenpai’s on 2026-08-29. Note that the Praveensenpai README recommends setting GTK_IM_MODULE=fcitx and hand-editing the fcitx5 profile, and neither is right on Omarchy 4. Third-party plugins run as unsandboxed code inside your long-lived shell process, so read them before you enable them. See plugins run unsandboxed.

Related

• Keyboard layouts and locale
• Non-US keyboard layout at LUKS and SDDM
• Chinese input with fcitx5