Jeong-min has a constant relationship with Mi-na, a man and woman on conditional terms, but he gets tired of her as she is gradually changing. He meets a new woman named Joo-hee under a new condition. Meanwhile, Mi-na spends a good time with her other boyfriend, Seong-mo. Then one day, Jeong-min hears the news that his friend Seong-mo has moved, so he goes to his housewarming party with Joo-hee and is surprised that Mi-na was also there.