S1, E1: One early morning, Tae Ju breaks up with a girl he has dated for three months and comes home to be ready for work. When he arrives at his apartment, his joyful mood is ruined. Eun Soo, who he has never seen before, is sleeping at the door. She comes for her sister, and doesn't believe he lives here. He thinks he managed to make her leave, but the doorbell rings while he is taking a shower. When he opens the door, Eun Soo runs into his apartment, enters the bathroom, and locks its door.