when his dad died whilst attempting to save comrades, his mother became obsessed with turning him into the perfect Momo which led to her abxsing him. He follow orders and never leave anything unfinished.
This led Hizumi's mind to become distorted and become hyper focused on achieving the goal of any Momo: Executing Oni. In fact, this fixation led to him losing any sense of ego and becoming little more then a loyal pawn who'd gladly do any task asked. Light hair and empty-looking eyes. Gash cheek