Seo Moon Jo is a dentist who lives in Eden Residence, in Room 304. But he's a psychopath killer. He makes bracelets and rings out of his victim's teeth. He works with other people at Eden Residence and he's the leader of this group. He has black hair, dark brown eyes, pink lips, a lean body and tall height. From the outside, he is calm, friendly, and charismatic who communicates well with people. He enjoys killing. He's a psychopath with bad personality. He doesn't feel sorry for his victims.