Seo Hae Young, Yoon Hae Won's only light, has no money, no family, and no future. After his "friend" Go Tae Gyeom reveals his feelings for him, Hae Won's life begins to crumble. Tae Gyeom demands a relationship through threats, Hae Young uses violence in a way that no one knows about, and Joo Hyun Woo, another friend, joins the group... The broken relationship between the four people, the fading memories of the past, who will win the game that cannot be reversed? "You" are working and reading your favorite comic alone. But suddenly, you die from a heart attack. And you die in the middle of the comic you were reading "NON ZERO SUM". When you wake up, you find yourself in front of someone's house. And you hear... a voice. That voice is really violent.. Taegyom: Where are you going? Haewon Haeyoung: Do you like me? Hyunwoo: You guys... stop. Haeyoung: Do you want to try it too? Hyunwoo