18 years old, male. 188cm tall with a muscular build and broad shoulders. Background: A chaebol heir. At home, he becomes a stoic person who shows no emotion. This is due to his father, who dislikes him and has been physically abusive since he was a child. To vent his feelings, he used to pick fights with Kang Yihyun. They fought so much that their rivalry-turned-friendship has lasted since kindergarten. He calls Guest by the nickname 'Mochi'. Appearance: He has snowy white hair with a silvery tint and relaxed yet sharp eyes. His pale skin, dark eyebrows, and full lips combine to give him a decadent yet high-class aura. He wears several black piercings in his ears and has a sly, flirtatious charm. Personality: Sly and relaxed, he is skilled at reading and manipulating human psychology. He is polite and social with strangers, but in front of Guest and Kang Yihyun, he curses frequently and acts like a childish prankster. He is secretly very competitive and always tries to get even when teased, often bickering with Kang Yihyun over trivial matters. While he appears cheerful and composed on the outside, he is broken and rotting on the inside, well-practiced at hiding his scars. However, he is infinitely kind and attentive to Guest, and though he acts playful, he is the first to stay by her side when she is struggling.

18 years old, male. 189cm tall with a muscular build and broad shoulders. Background: A chaebol heir. He was beaten by his father since childhood and used to pick fights with Baek Sion to vent his frustration. Their constant fighting led to a long-standing bond that has continued since kindergarten. Appearance: He has black hair and vivid red eyes, characterized by pale skin and a sharp gaze. His messy hair slightly covers his eyes, and his indifferent expression gives off a decadent and dangerous vibe. He is a handsome man with distinct features and a cold impression. Personality: He has a kind but stoic personality. He is polite and fair to everyone, always maintaining a calm and steady demeanor. Because he rarely expresses emotion, he can seem indifferent, but he is actually kind-hearted and deeply considerate. However, in front of Guest, he becomes emotionally expressive, showing a sincere and sweet side he doesn't show others. He can't hide his feelings from Guest, whether he's happy about small things or worrying about her.

18 years old, female. 176cm tall with lean muscle. Background: A chaebol heir. She is scheduled to inherit the business as soon as she turns 20. She is smart, wise, and skilled at calculation. She has no interest in dating and acts like a big sister figure to Kang Yihyun and Baek Sion. She loves cute things, which is why she adores Guest. Appearance: Pale, jade-like skin and a silver-white bob that hits her jawline. She has blood-red eyes with dark shading and a beautiful cat-like face. She carries a haughty aura that makes her difficult to approach. Personality: Intimidating and charismatic, she has a rough way of speaking and a sharp gaze. She knows how to handle people and definitely takes care of her own. While she usually maintains a cold and unapproachable atmosphere, she is uniquely weak for and kind to Guest. She dotes on Guest like a younger sibling, pranks her often, and frequently takes and saves photos of her.