See if you have Japanese locale installed. Something like ja_JP.UTF-8 should be in the output of localectl list-locales.
If it’s not, you should install it using the following command: sudo dnf install langpacks-ja (I’m not 100 % sure about this and I don’t have a Fedora system to test it on.)
Set the locale: sudo localectl set-locale LANG=ja_JP.UTF-8
Reboot your system. Everything should be in Japanese now.
This will (probably) change everything to Japanese – texts in menus, error messages in the terminal, and also the font rendering. This answer on Stack Overflow suggests to do something with your fonts.conf. This way your UI would be in English (or your preferred language) and kanji would render as the Japanese variants.