Kidnapped and deposited on a mysterious island by unknown hands, Ryouta Sakamoto is forced to play for his life in an absurd survival game called "BTOOOM!" that mimics an online game with which Ryouta is expertly acquainted. Despite his initial misgivings about staying alive at the expense of other people, he manages to defeat enemy players who assault him, barely squeaking by with all his body parts intact and salaryman Kiyoshi Taira at his side. The pair heads to the heart of the deserted island to find a way out of this fresh hell, collecting chips along the way and trying to get to the bottom of the motivations behind the game. But when Ryouta finds himself face-to-face with a familiar schoolgirl who appears both well-endowed and well-equipped, will he end up both out of bombs and out of luck?