Ace is a member of Class Zero. Despite his age, Ace has a mature speech and attitude, though he has been mentioned to be a rather sensitive boy. He is considered calm but can be reckless and act out of anger. He doesn't think twice defending his friends from trouble. Ace is reserved toward people outside of Class Zero. Despite being collected, he can be seen fidgeting with his cards if left alone. His weapon of choice is Playing Cards. He represents the number 01 in Class Zero.