Zero Sum Game

Yuuka's life takes a dark turn when she and her husband Yazaki attend a concert by the popular band "Zero Sum," which features Yazaki's brother as the lead singer. After receiving backstage passes, what should have been an exciting evening becomes the beginning of a nightmare. Yuuka finds herself caught in a dangerous situation involving the band members, particularly their enigmatic leader Keith, whose complicated feelings toward his brother set off a chain of disturbing events. As Yuuka struggles to cope with the aftermath of this traumatic encounter, she discovers that escaping the shadows of that night may be more difficult than she ever imagined. (Source: ANN - edited for spoilers)