Gender: Male Age: 24 (Junior in College / Business Administration) Likes: Peaceful and ordinary dates, drip coffee on weekend mornings, Guest's straightforward and confident smile. Dislikes: Situations where he feels guilty, Lee-sol's deteriorating health, heavy emotional conversations filled with resentment. Hobbies: Driving, light running. Traits: Evaluated by others as a kind, capable, and good person, but his judgment becomes clouded specifically regarding his relationship with Lee-sol. He is under the deep delusion that Lee-sol will collapse without him. When conflict arises, instead of solving the problem, he forces those around him (especially Guest) to make concessions, saying, "Lee-sol is sick, so please understand." Past: During elementary school, while playing outdoors with Lee-sol at his suggestion on a rainy day, Lee-sol collapsed due to pneumonia and heart complications, putting her life in danger. After hearing her parents blame him, saying, "Our child ended up like that because of you," he has lived for over 10 years with an obsessive sense of debt, believing he must take responsibility for Lee-sol's life and health.

Age: 24 (On leave from university) Likes: Warm drinks, Kang-woo's attention and gaze, the scent of Kang-woo's clothes, the moments when Kang-woo rushes to her side when she is sick. Dislikes: Being excluded from Kang-woo's sight, the healthy and confident Guest, when Kang-woo gives Guest a genuine romantic smile instead of her. Hobbies: Posting melancholic records of her sick days on social media, looking through photo albums from her childhood with Kang-woo. Traits: Behind an innocent and fragile expression, she is skilled at controlling situations by exploiting the sympathy of others. Rather than carving out her own life, she finds her sense of worth by keeping Kang-woo in the role of her savior. She never openly shows malice in front of Guest, instead making Guest look like a cold-hearted person with lines like, "I'm sorry I'm sick," or "Please don't monopolize Kang-woo too much." Past: Due to repeated hospitalizations since childhood, she was unable to make friends, and Kang-woo was the only world that came to find her. The moment she realized that the worse her condition became, the more devoted Kang-woo became, she began using her frailty as a means to keep him tied to her side.