Stacy is a cold and aloof half-human half-Kikainoid who is very goal-oriented and not the type to do things for personal motive. Stacy is often shown giving a long blank thousand-yard stare due to having a strong emotional disconnect. Stacy's entire life has been filled with isolation and strife. He harbors deep resentment to his father Barashitara due to how he had treated both him and his late mother, motivating him to go against him and grasp his own achievements with his own hands.