1x7 - Summer Strike

Dae-beom and Yeo-reum get closer by the day, and it is not easy for Ji-young to watch them from afar. One day, Dae-beom takes Yeo-reum home after having a great time together, and he runs into writings regarding her sister on the wall of Sunah Billiard. Yeo-reum is worried about him, but that's about all she can do for him. The next day, Dae-beom does not show up at the library.