Till The Break Of Day(2014)

13 year old girl, Hyeju has to spend a few days with her highschool student brother while her parents are absent. By the way, her brother brings his girlfriend home and lets Hyeju out. Hyeju doesn´t know where to go, so she comes back home after killing time somewhere like PC room. Next morning, she finds used condom in bro´s room with curiosity. And she finally has a date with a highschool boy who she could meet through the online chat, but it is awkward and uncomfortable somehow.