I’m trying to find a way to change the font used in Gnome3 when using the Japanese(Anthy) input method. I added Japanese(Anthy) as an Input Source under Settings → Keyboard.
I ran ibus-setup and selected a custom font, but when I switch to Japanese (Anthy) it still used the default font.
ibus-mozc with GNOME seems to work smoothly. The only strange thing that without selecting XFCE during a fresh installation the make process fails.
yay -S ibus-mozc
and accepted defaults
(It took me cca 15 min. to install on Lenovo IdeaPad S145-15IIL )
DE: GNOME 40.5
/ibus-mozc 2.23.2815.102-3 (+64 1.59)
what i did to set it up:
Install anthy: yay -S ibus-anthy
Run: ibus-setup
Add lines to the .bash_profile:
export GTK_IM_MODULE=ibus
export XMODIFIERS=@im=ibus
export QT_IM_MODULE=ibus
setup anthy at my likings adding the custom font: SourceSansHanJPBold
after that i settup the keyboard on the system by doing:
configuration>keyboard>add keyboard
you add the keyboard and once you do it you´ll just need to click on the key right below to the [ESC] key, it should change the characters displayed to Hiragana or Romanji depending on what font you want to use, have luck and i hope this helped even a bit
Atte: Lilly さよなら [goodbye]
[edit:] the Kana/Romanji change key works for my keyboard distribution, it could change for yours depending on your keyboard distribution
thanks and welcome @JossDev-Lilly 
Would be better to create a new post with a useful title as… only users subscribed to this thread will get the notification for a 2 years old thread…
sorry for the error, and thanks for the suggestion, i´ll do the post
no errror 
only suggestion and normal you are new here so not an issue in any way!