Natsuki Subaru is summoned to a parallel world on his way home from the convenience store. He's entranced at first by the fantasy world suddenly stretching before his eyes, but the cute girl he believes summoned him is nowhere to be found, and soon enough he's utterly lost. Then a gang of punks surrounds him, but he quickly learns that he doesn't have any of the powers that he thought all people transported to a parallel world should have. Just when he's about to be beaten senseless, a girl appears...

Suddenly, high school student Subaru Natsuki has been summoned to another world on the way back from the convenience store. With the biggest crisis of his life being summoned to another world, and with no sign of the one who summoned him, things become even worse when he is attacked. But when he is saved by a mysterious, silver-haired girl with a fairy cat, Subaru cooperates with her to return the favor. When they finally manage to get a clue, Subaru and the girl are attacked and killed by someone. Subaru then awakens in the place he was summoned and notices he gained the ability "Returns by Death" and has become a helpless boy that only has the ability to rewind time by dying. Beyond the despair, can he save the girl from the fate of death?