Explanation is lengthy but basically: A fan replied to her and spelled her nickname wrong, which she corrected. He then acted offended that she corrected him and insisted that his spelling was correct, which it wasn't. He called her a dumb returnee who doesn't know proper Japanese, so she blocked him. This made him angry, for some reason he threatened to call the police (???) and then stopped talking about it for a few days.

Today he started going off again saying that she's a disgrace to professional wrestling, which caught the attention of another fan who chastisted him over it. Kamiyu saw this tweet and liked it, so the guy took it as her directing harassment towards him, which culminated in him using a second account to pose as someone else, and claimed that she directed fans to target "his friend" to the point that "his friend" attempted suicide. The tweet has since been deleted but the account is still active.

And it turns out that this fan is known among Japanese fans for being insane and doing shit like this, his nickname is "Uncle Clippers" because he once threatened over Twitter to stab a fan at a Stardom show with clippers, which resulted in the police becoming involved.