Sang-hee in her early teens wakes up in the morning one day and goes to the bathroom to bump into a naked guy, who says hello in an awkward way. Sang-hee never dares to ask her mother about him, and her mother also avoids explaining and tries to avoid her. The adolescent girl just about to step out into the world copes with her first menstruation on her own, and at the same time, develops interests in men. (Kim Hea-seung)