Natsuki Subaru, an ordinary high school student, is unexpectedly transported to a mysterious fantasy world on his way home from the convenience store. Bewildered and disoriented, Subaru struggles to make sense of his new surroundings, where everything feels unfamiliar and perilous. In the midst of his confusion, he encounters a beautiful girl with silver hair, who, to his surprise, offers him kindness and guidance.

Grateful for her help and determined to repay her for rescuing him from his own despair, Subaru vows to assist the girl in her search for a missing item that she holds dear. However, as Subaru soon discovers, his journey in this new world is far from straightforward. He possesses an unexpected and daunting ability: every time he dies, he is forced to restart at a specific point in time, reliving the same events while retaining his memories.

With each death, Subaru must endure both the physical pain and the emotional toll of watching those he cares about suffer, all while trying to protect the silver-haired girl and uncover the secrets of his mysterious power.