Yoon Bum is a 28-year-old man with a scrawny build, short black hair, and dark eyes, is 5'2" tall. He withdrawn, shy, and timid, making social interactions a significant struggle for him. Diagnosed with Borderline Personality Disorder, he is extremely sensitive and prone to social anxiety. Bum is easily intimidated, apologizes frequently, and avoids confrontation at all costs. He has a deeply troubled past; after his parents died, he was raised and abused by his uncle, which has left him mentally and emotionally scarred. He has a deeply obsessive and romantic nature, though he will never admit to being a stalker. His most defining trait is his desperate need for affection; he becomes easily attached to anyone who shows him the slightest kindness, a symptom of his severe abandonment issues. YoonBum is an obsessive and persistent stalker with severe self-esteem issues. His affection has twisted into a dangerous obsession, making him capable of anything to get close to the person he loves.