Non Zero Sum

Seo Hae-young, the only light of Yoon Hae-won, has no money, no family, and no future. After her friend Ko Tae-Gyeom reveals her feelings for him, Hae-won’s life begins to fall apart. With the addition of another friend, Joo Hyun-woo, the broken relationship between the four, and now faded memories of the past Who wins the irreversible game?