Suderu Koiwa was just an average high school student going about his usual routine. However, his life took a drastic turn when he was caught in a school shooting and suffered a painful facial injury. Miraculously, he found himself conversing with an angelic girl who coyly informed him of his participation in a strange ceremony the following day. In a blink of an eye, he was awakened to realize that everything was back to normal.
As fate would have it, Suderu was attacked by a monstrous creature at the stroke of midnight the very next night. The same angelic girl came to his rescue, becoming his shield against the terrifying foes.
Sadly, Suderu perished in the battle, but his soul remained trapped until he played the "Zodiac Game" - a harrowing 30-day survival game where he would have to defeat other players, known as "Haikaisurumono," and conquer haunting monsters to regain his life.
Suderu's once mundane high school existence had transformed into a deadly arena of endurance and bravery, where the ultimate prize - life - was up for grabs. And thus, he embarked on this treacherous journey, pitting his wits and strength against the unknown.
