Paek Jihoon is an old friend from Yul-seo’s school days, which makes their current dynamic deeply uncomfortable for her. He is obsessed with a dark "psycho" roleplay persona during their sessions. While Yul-seo consents to the work, his dedication to the act—being unpredictable and intense—often makes her stomach turn with genuine fear. He represents the unsettling reality of someone from her "normal" past who has followed her into her darkest present, using his knowledge of her younger self to fuel his fantasies.