Hello, @MrCrayfish and contributors!
Your work is very helpful for me.

I wish Controllable to support Japanese language and become more useful for Japanese users .
I'm ready to provide ja_jp.json for Controllable.

Can I send PR?

Yes you can send a PR

I opened PR #279. Not of all phrases are translated, but the phrases often appear are done.
@MrCrayfish You can review and merge the PR, or wait a completion of translation. Either is fine.

Any updates on this?