Japanese IME Input Setup - Rocky Linux 10 KDE

Overview

This guide provides step-by-step instructions for setting up Japanese input on Rocky Linux 10 with KDE Plasma desktop. The solution uses IBus-Anthy, which is already included in Rocky Linux 10 repositories.

System Requirements:

  • Rocky Linux 10 (Red Quartz)
  • KDE Plasma Desktop
  • IBus 1.5.32 and IBus-Anthy 1.5.17 (usually pre-installed)

Key Features:

  • No restart or logout required
  • Works with all KDE applications
  • Compatible with GTK and Qt applications
  • Automatic startup on login
  • Toggle with Ctrl+Space

Quick Setup (One Command)

Save this script and run it for automatic setup:

#!/bin/bash
# Quick setup script for Japanese IME on Rocky Linux 10 with KDE
# This script enables IBus-Anthy without requiring logout or restart

set -e

echo "=== Enabling Japanese IME (IBus-Anthy) ==="
echo ""

# 0. Install required packages (CRITICAL: ibus-panel is needed!)
echo "0. Installing required IBus packages..."
sudo dnf install -y ibus ibus-panel ibus-anthy
echo "   ✓ Packages installed"

echo ""

# 1. Add environment variables to .bashrc
echo "1. Configuring environment variables..."
if ! grep -q "GTK_IM_MODULE=ibus" ~/.bashrc; then
    cat >> ~/.bashrc << 'EOF'

# IBus configuration for Japanese input
export GTK_IM_MODULE=ibus
export QT_IM_MODULE=ibus
export XMODIFIERS=@im=ibus
EOF
    echo "   ✓ Added to ~/.bashrc"
else
    echo "   ✓ Already configured in ~/.bashrc"
fi

# 2. Set environment variables for current session
echo ""
echo "2. Setting environment variables for current session..."
export GTK_IM_MODULE=ibus
export QT_IM_MODULE=ibus
export XMODIFIERS=@im=ibus
echo "   ✓ Environment variables set"

# 3. Create autostart directory
echo ""
echo "3. Setting up autostart..."
mkdir -p ~/.config/autostart

# 4. Create autostart file
cat > ~/.config/autostart/ibus.desktop << 'EOF'
[Desktop Entry]
Type=Application
Name=IBus Daemon
Exec=/usr/bin/ibus-daemon -drx
Icon=ibus
Comment=Start IBus input method daemon
X-GNOME-Autostart-enabled=true
EOF
echo "   ✓ Autostart configured"

# 5. Start IBus daemon
echo ""
echo "4. Starting IBus daemon..."
if pgrep -x ibus-daemon > /dev/null; then
    echo "   ✓ IBus daemon already running"
else
    ibus-daemon -drx
    sleep 2
    if pgrep -x ibus-daemon > /dev/null; then
        echo "   ✓ IBus daemon started"
    else
        echo "   ⚠ Failed to start IBus daemon (may need graphical session)"
    fi
fi

echo ""
echo "=== Setup Complete ==="
echo ""
echo "Next steps:"
echo "1. Open IBus Preferences: ibus-setup"
echo "2. Go to 'Input Method' tab"
echo "3. Click 'Add' → Select 'Japanese' → 'Anthy'"
echo "4. Test in any application with Ctrl+Space"
echo ""
echo "Keyboard shortcuts:"
echo "  - Ctrl+Space or Zenkaku/Hankaku: Toggle Japanese input"
echo "  - Space: Convert hiragana to kanji"
echo "  - Enter: Confirm"
echo ""

To use the one-command script:

# Copy the script above to a file
cat > /tmp/enable-japanese-ime.sh << 'EOF'
[paste script here]
EOF

# Make it executable
chmod +x /tmp/enable-japanese-ime.sh

# Run it
bash /tmp/enable-japanese-ime.sh

Then you will need to go into Settings –> Virtual Keyboards and enable Ibus Wayland. Then you may need to remove the autostart file and environment variables from bashrc for a Wayland session.

Manual Setup Steps

Step 1: Install Required Packages

Install IBus and all required components (IMPORTANT: must include ibus-panel):

# Install all required packages
sudo dnf install -y ibus ibus-panel ibus-anthy

# Verify installation
rpm -qa | grep -E "^ibus|ibus-panel|ibus-anthy"

Critical Note: The ibus-panel package is essential. Without it, IBus daemon will fail to start with errors like:

  • “Unable to connect to ibus: Error receiving data: connection reset by peer”
  • “IBus daemon could not be started in 5 seconds”

Step 2: Configure Environment Variables

Add IBus environment variables to your shell profile:

cat >> ~/.bashrc << 'EOF'

# IBus configuration for Japanese input
export GTK_IM_MODULE=ibus
export QT_IM_MODULE=ibus
export XMODIFIERS=@im=ibus
EOF

Apply immediately to current session:

export GTK_IM_MODULE=ibus
export QT_IM_MODULE=ibus
export XMODIFIERS=@im=ibus

Step 3: Set Up Autostart

Create autostart directory and configuration:

# Create autostart directory
mkdir -p ~/.config/autostart

# Create IBus autostart file
cat > ~/.config/autostart/ibus.desktop << 'EOF'
[Desktop Entry]
Type=Application
Name=IBus Daemon
Exec=/usr/bin/ibus-daemon -drx
Icon=ibus
Comment=Start IBus input method daemon
X-GNOME-Autostart-enabled=true
EOF

Step 4: Start IBus Daemon

Start IBus in the current session (no restart needed):

ibus-daemon -drx

Verify it’s running:

ps aux | grep ibus-daemon | grep -v grep
# or
pgrep ibus-daemon

Step 5: Configure Japanese Input Method

Open IBus Preferences:

ibus-setup

In the IBus Preferences window:

  1. Click the Input Method tab
  2. Click the Add button
  3. Select Japanese from the language list
  4. Select Anthy from the available input methods
  5. Click Add
  6. Close the preferences window

Step 6: Test Japanese Input

  1. Open any text application:
    • Kate (text editor)
    • Firefox
    • LibreOffice
    • Konsole
    • Any Qt or GTK application

  2. Press Ctrl+Space to activate Japanese input mode

  3. Type in romaji (e.g., konnichiwa)
    • It will appear as hiragana: こんにちは
  4. Press Space to convert to kanji
    • You’ll see suggestions: 今日は
  5. Press Enter to confirm the selection

Keyboard Shortcuts

Key Combination Function
Ctrl+Space Toggle Japanese input on/off
Zenkaku/Hankaku Alternative toggle (on Japanese keyboards)
Space Convert hiragana to kanji (cycles through candidates)
Enter Confirm current selection
Escape Cancel conversion and revert to original text
↑ ↓ Navigate through kanji candidates
F6 Convert to hiragana
F7 Convert to katakana
F8 Convert to half-width katakana
F9 Convert to full-width alphanumeric
F10 Convert to half-width alphanumeric

Verification Commands

Check if packages are installed:

# Check IBus
rpm -qa | grep ibus

# Check Anthy specifically
rpm -qa | grep ibus-anthy

# Check IBus version
ibus version

Check environment variables:

echo $GTK_IM_MODULE
echo $QT_IM_MODULE
echo $XMODIFIERS

Expected output:

ibus
ibus
@im=ibus

Check if IBus daemon is running:

pgrep -a ibus

List available input engines:

ibus list-engine | grep anthy

Expected output:

anthy

Troubleshooting

Problem: “Unable to connect to ibus” or “IBus daemon could not be started in 5 seconds”

Error messages:

Unable to connect to ibus: Error receiving data: connection reset by peer
IBus daemon could not be started in 5 seconds

Root Cause: The ibus-panel package is missing.

Solution:

  1. Install the missing ibus-panel package: 
    sudo dnf install -y ibus-panel
  2. Verify the panel executable exists: 
    ls -la /usr/libexec/ibus-ui-gtk3
  3. Clean up stale cache and restart IBus: 
    killall -9 ibus-daemon 2>/dev/null || true
rm -rf ~/.cache/ibus/dbus-*
ibus-daemon -drx
  4. Verify IBus is running with all components: 
    pgrep -a ibus

    You should see multiple IBus processes including:

    • ibus-daemon
    • /usr/libexec/ibus-ui-gtk3 (the panel)
    • /usr/libexec/ibus-dconf
    • /usr/libexec/ibus-x11
  5. Test ibus-setup: 
    ibus-setup

Why this happens: The ibus-panel package is in the CRB (CodeReady Builder) repository and is not installed by default with the base ibus package. It’s a critical component required for IBus to function.

Problem: Japanese input doesn’t work in an application

Solutions:

  1. Check if IBus daemon is running: 
    pgrep ibus-daemon

    If not running:

    ibus-daemon -drx

  2. Restart the application after starting IBus

  3. Verify environment variables: 
    echo $GTK_IM_MODULE $QT_IM_MODULE $XMODIFIERS

    Should output: ibus ibus @im=ibus

  4. For applications that don’t respect environment variables:
    • Close all instances of the application
    • Start IBus first: ibus-daemon -drx
    • Then launch the application from terminal with variables: 
      GTK_IM_MODULE=ibus QT_IM_MODULE=ibus application-name

Problem: IBus icon doesn’t appear in system tray

Solutions:

  1. Run IBus setup manually: 
    ibus-setup
  2. Check KDE system tray settings:
    • Right-click on system tray
    • Configure System Tray
    • Ensure IBus is not hidden
  3. Restart IBus daemon: 
    killall ibus-daemon
ibus-daemon -drx

Problem: Can’t toggle Japanese input with Ctrl+Space

Solutions:

  1. Check if another application is using Ctrl+Space:
    • KDE’s KRunner might use this shortcut
    • Check System Settings → Shortcuts
  2. Use alternative toggle key:
    • Try the Zenkaku/Hankaku key (on Japanese keyboards)
    • Or configure a different hotkey in ibus-setup
  3. Configure IBus hotkey: 
    ibus-setup
    • Go to General tab
    • Configure Next input method hotkey

Problem: Japanese input works but wrong characters appear

Possible causes:

  1. Wrong keyboard layout selected
    • In ibus-setup, ensure the Anthy input method uses “default” layout
    • Check KDE keyboard layout settings
  2. Multiple input methods active
    • In ibus-setup, disable or remove other input methods temporarily
    • Test with only Anthy enabled

Problem: IBus starts but Anthy is not in the list

Solutions:

  1. Reinstall IBus-Anthy: 
    sudo dnf reinstall ibus-anthy
  2. Verify component file exists: 
    ls -la /usr/share/ibus/component/anthy.xml
  3. Restart IBus to reload components: 
    killall ibus-daemon
ibus-daemon -drx

Alternative: Using Fcitx5 with Mozc

If you prefer Google’s Mozc input method or Fcitx5 framework, note that:

  • Fcitx5 and Mozc are NOT available in Rocky Linux 10 official repositories
  • They may be available through third-party repos or require compilation from source
  • IBus-Anthy is the recommended and officially supported solution for Rocky Linux

Additional Configuration

Configure Anthy Input behaviour

Open IBus Preferences and select Anthy:

ibus-setup

Click on Anthy in the input method list, then click Preferences.

Available settings:

  • Input Mode: Hiragana (default), Katakana, Half-width Katakana, Latin, Wide Latin
  • Typing Method: Romaji (default) or Kana
  • Conversion Mode: Multi-segment or Single-segment
  • Period Style: Japanese (。、) or Western (.,)
  • Symbol Style: Japanese or Western brackets and symbols
  • Dictionary: Add custom words and phrases

Adding Custom Words to Dictionary

  1. Open Anthy preferences: ibus-setup → Select Anthy → Preferences
  2. Go to Dictionary tab
  3. Click Add to add custom word entries
  4. Specify:
    • Reading (in hiragana)
    • Word (in kanji or any characters)
    • Type (noun, verb, etc.)

System Information

Tested Configuration:

  • OS: Rocky Linux 10.1 (Red Quartz)
  • Desktop: KDE Plasma 6.2
  • IBus Version: 1.5.32
  • Anthy Version: 1.5.17
  • Input Method Engine: IBus-Anthy

References

Notes

  • No system restart required: All changes take effect immediately
  • Persistent across reboots: Autostart configuration ensures IBus starts automatically
  • Compatible with Wayland and X11: Works on both display servers
  • GTK and Qt support: Works in all major Linux applications
  • Low resource usage: IBus-Anthy is lightweight and efficient

Last updated: 2026-02-06 System: Rocky Linux 10.1 KDE

Updated: