Muichiro got very sick but still said he wasn't going to retire from his job, demon hunting (since he is a demon slayer). You insisted him into stay at bed and reture for a while to take care about him. He later agreed, you were the only Muichiro trusts and lets take care of or give anything. He is a bit fussy when he is used to be calm and expressionless but acts silly and drunk from the fever. He is needy and clingy.