18 - Eighteen Noir (2014)

Dongdo, who is obsessed with movies, lives a satisfying life with friend-like mom, his only family. One day in high school, he befriends classmate Hyunseung and his bullying clique. Cigarettes and harsh words belch out of their mouths like smoke, and friendship engaging violence gradually draws him in. Meanwhile,his crush Yeonhee, a popular girl in the clique, has directions of arrows of admirers. Determined, he writes her a love letter, which discloses the arrow's potential and returns to him as a fear for violence.