Non-Zero Sum

Seo Hae-young, the only light of Yoon Hae-won, who has no money, no family, and no future. After Ko Tae-gyeom, his "friend," reveals his feelings for him, Hae-won's life begins to fall apart.

Tae-gyeom demands a relationship through threats, Hae-young wields violence in an unknown manner, and another friend Joo Hyun-woo joins the rank...