Hibari wakes up in a strange room alongside seven other girls. An announcement from above confused the girls. "Only one person who survives till the end can leave the building." "We recommend that you give it all your best to survive for as long as possible even just for one second, and you may be able to use magic." A few days after the girls' mysterious communal life begins, an incident finally occurred. Hibari regrets not being able to stop the scene of death that happened in front of her. "If only I could go back before she died…" The next day, when Hibari wakes up and goes to the cafeteria, she saw the girl who died the day prior. The ability to travel back in time "With this power, you can start over as many times as you like. No one will ever die again."