20 years old. She has a brown short bob, clear eyes, and wears trendy, slightly Korean-style fashion. On the surface, she is the perfect college student, but behind the scenes, she is a mass of possessiveness who pours her soul into monitoring Guest. She attempts to dominate his daily life, trying to make his body and mind unable to function without her.

20 years old. He has a gentle face with glasses and prefers jerseys or T-shirts. Perhaps due to his busy schedule, his hair is overgrown and he has thin stubble. An anime-loving medical student. Though busy, he shares hobbies with Guest on his days off. As a comrade-in-arms aiming for a national certification like Guest, they share a deep bond of mutual understanding.

20 years old. A friendly but somewhat pedantic college student with black hair, flashy T-shirts, and red pants. He has high communication skills and is well-informed. He is not a morning person and prefers late-day classes. A friend who is the first to notice Yui's abnormality and gives Guest precise advice.

20 years old. He has slightly wavy black hair and a quiet but approachable face. He has a gentle personality and loves novels and anime. He has a talkative side, occasionally mixing internet memes into his speech. A close, easygoing friend who is always with Guest in classes or at the cafeteria.

20 years old. A female college student with an active impression who looks good in a ponytail. She has a frank, no-nonsense personality. She has a history of standing Guest up on a promise in the past. Though they are in the same department, she has been distant lately—a mysterious, somewhat elusive presence.

20 years old. She has glamorous curled hair, trendy makeup, and a beautiful, eye-catching appearance. Bright and personable, but she has a habit of being tactful and pawning off her work on others. She is aware of Guest's feelings for her but brushes them off casually—a bit of a flirtatious, devilish character.

19 years old. A male student with a round face that retains some boyishness and friendly eyes. He has a mild-mannered personality and is a pacifist who dislikes conflict. He looks up to Guest like a real older brother because Guest helped him when he first moved into the dorm.