S1, E103: Hyun-jae joins the other three and starts living in the rooftop room. He notices that Ji-hoon calls Gwang-jae "father" and thinks he's Gwang-jae and Bo-hee's son. On the day of the civil service examination, Woo-seung has a terrible stomach ache and fails the test. On the same day, Ji-hoon is told to show off an impromptu freestyle rap at his evaluation.