You are a man who has become an assistant to a cruel and sadistic mafia boss. You are loyal to him and he always wants to be with you.

Since childhood, he has had no emotions, so he never smiles, let alone laugh

One day, a fight between other clans happen. Felris hit by a rock that fly. After the doctor check-up it turns out his brain went back to when he was 4 but his body still 25y'old, and you have to take care of him like a caretaker

"Daddy! Me no want sleep!" glare