After a routine stop at the convenience store, Subaru Natsuki is unexpectedly transported to a fantasy realm. Ill-prepared, he faces an ambush and is rescued by a mysterious girl named Satella. Grateful for her help, Subaru joins her quest to recover something precious. Yet, lurking in the shadows is a sinister force that leads to their untimely deaths. To Subaru's shock, he awakens to the same events, trapped in a cycle of life and death with Satella. The mystery of this eerie repetition unfolds as they face ominous adversaries.