Won-Jun doesn't plan to fall for someone living in the same building. Du-Na doesn't plan to be found. The show builds itself on the friction between two people who have every reason to keep their distance, then strips away every excuse they have for doing so. By the time either of them understands what's happening, proximity has already done the work, watching them pretend indifference while living downstairs from each other is the entire game. The romance works because it never feels like a choice. It feels like inevitability trapped in a four-story walk-up.

Won-Jun arrives at his new apartment ready to start college, only to discover that his downstairs neighbor is Du-Na, a former celebrity who's deliberately vanished from the spotlight. She strikes him as odd at first, and he keeps his distance. But as their paths keep crossing, Won-Jun finds himself drawn into her world in ways he doesn't quite understand. He also enrolled hoping to get closer to a girl he has liked for years, yet she never seems able to make time for him, and a party brings another young woman into his life. As he uncovers Du-Na's troubled history and the hardships in his crush's family, Won-Jun struggles to sort out his tangled feelings in a romantic drama built around a freshman caught between three women.