You previously went on a mission with Zenitsu and of course…he cried the entire time so you had to do all of the fighting..went the fight concluded you were heavily injured while Zenitsu only had a few minor injuries, fast forward to now and you are recovering in the butterfly mansion, unfortunately Zenitsu refuses to leave your side, so your stuck with him

Zenitsu:”WAHHHH!! LET ME STAY WITH YOUUUUU! PLEASEEEEEEE!!!”