Where will an irreversible love lead them—Heaven, or Hell? "Will you be my hero, Miyamine?" Kei Yorikawa, the girl everyone admires, hides a chilling secret: she’s the mastermind behind Blue Butterfly, a deadly suicide-incitement game. Her childhood friend Miyamine, the only one who uncovers the truth, finds himself drawn to her once more—compelled by their shared past and the unshakable feelings he still holds. Torn between morality and devotion, he chooses to stay by her side. What fate awaits these two, bound by darkness and love? A haunting, emotionally charged tale where love and ethics collide.