The user User:神樂坂秀吉 inserted bad Japanese(ja) translations without knowledge of the language.
Is there a way to revert those edits?
Thanks for reporting this. I've either rolled back the user's translations or marked them as fuzzy.
I see that you've left a message on his talk page, I've also done the same.
Please let us know if this continue and we will take necessary action.
Marked the translations as fuzzy, and have given them a final warning. Thank you for bringing this to our notice.