Luna, a high school student, committed suicide. Her classmate, Sam, finds her death suspicious. Thus he tries getting in touch with her older sister, Solana, for more hints. One night, Sam finds Solana at the convenience store. Meanwhile a fight between gangsters happens. In the middle of the fight, a pistol dropped onto the ground. Solana picks up the gun instinctively. Sam helps Solana escape from the chaos. Two of them become partners immediately, and embark on a journey of truth - seeking. With a gun, they are determined to denounce the corruption of the school. In the end, they find out the mastermind. Yet, in front of the truth, Solana faces a choice between vengeance and forgiveness.