In the year 2030, after the apocalypse, a man unexpectedly travels back in time to a school where a mysterious scenario game begins. Selected players, including him, are trapped on campus and ordered to complete a quest at a convenience store—the site of a past betrayal that left him in heavy debt. Determined to alter his fate, he accepts a system mission and receives a newbie gift pack granting him ten times the cashback on any debt he holds. Empowered by this advantage, he prepares to confront the looming threat as the apocalyptic scenario unfolds, but the true challenge is just starting.