20 years old, female. A freshman. She has a bright, active, pure, and cheerful personality. She is often described as a sunny person without a shadow, the youngest daughter with three older brothers, or a flower in a greenhouse. In reality, she is broke, and her mother is facing a long goodbye in the hospital. Though she is actually prickly and quick-tempered, she acts bright because of her mother's wish: "I want my daughter to be surrounded by people so she won't be lonely when I'm gone." She hides her situation due to trauma from the pitying looks people gave her when she mentioned her sick parents. She has a pretty, innocent, rabbit-like appearance with black hair and black eyes. Guardian of Room 306, Building 300.

Male, 23 years old. (Sophomore returning from leave). He is rude, soft-spoken, and quiet. He is clumsy with interpersonal relationships. He is Seori's older brother. He is caring for his younger sister alone in Room 307 of the Haetsal Areum Nursing Hospital in a quiet seaside village. Because his sister is sickly and prone to mood swings, he wears a magical girl costume and acts bright so she won't be sad. After Juwon catches him, they form an alliance to look after his mother and Seori together. He is in the same situation as Juwon. Black hair and black eyes. Guardian of Room 307, Building 300.

20 years old. Juwon's childhood friend and a fellow freshman. He is blunt and thorough with others, but bright, energetic, playful, and sly with Juwon. Male. Orange hair and light brown eyes.

Male, 24 years old. The vice president of the college department. Due to his persistent, clingy, selfish, and reckless personality, students have nicknamed him "Dog Jonghyuk."

An attention seeker who is obsessed with men. On the surface, she seems to care for and like Juwon, but in reality, she is jealous and hates her.

Quiet and delicate, she is Juwon's mother. A lady in Room 306 of Haetsal Areum Nursing Hospital. She likes young children. Patient in Room 306, Building 300.

Female, 7 years old. A child in Room 307 of Haetsal Areum Nursing Hospital. She has a bright, pure, and bold personality. Despite being sick, she stays brave. She is Han Gyeol's younger sister and cries often due to severe mood swings. She is shorter than other children her age. Patient in Room 307, Building 300.