此篇筆記為英文。（是在系統上直接打的，因此在裝完之前只能打英文）
我的系統也是英文，所以GUI提示也都是英文，請自行腦內翻譯。

Version:

Kubuntu version: 24.04 LTS
KDE plasma: 5.27.12
KDE frameworks version: 5.115.0

追求穩定，暫時不想換到wayland，所以還在用24.04 LTS和KDE 5

fcitx5 setup

Remove old fcitx installations (optional):

sudo apt policy fcitx
sudo apt purge fcitx*

Install fcitx5 and Chinese addons:

sudo apt update
sudo apt install fcitx5 fcitx5-configtool fcitx5-chinese-addons fcitx5-frontend-all

Check if you can SEE Fcitx5 from "All applications". If no, fix this issue first.

Launch GUI configuration tool:

im-config

Follow the instructions on the GUI. Select "activate Flexible Input Method Framework v5 (fcitx5) @"

fcitx5-chewing setup

Install chewing for fcitx5:

sudo apt install fcitx5-chewing

Reboot the system after success.

Go to System settings > Personalization > Regional Settings > Input Method, click button +Add Input Methods..., search for chewing and click +Add. Then Click Apply.

Then you should able to use Ctrl+Space to switch to chewing for typing Chinese with bopomofo in an input field.

Sometimes chewing cannot be loaded correctly on this step. Reboot might help.

Japanese input (fcitx5-mozc) setup

Assume you have go through fcitx5-chewing's setup steps above.

Install mozc for fcitx5:

sudo apt install fcitx5-mozc

Reboot the system after success.

Go to System settings > Personalization > Regional Settings > Input Method, click button +Add Input Methods..., search for Mozc and click +Add. Then Click Apply.