The story follows the daily life of Subaru Natsuki, a modern-day high school student who is transported into a fantasy world. He finds himself working with Emilia, a young woman with magical abilities, and befriending other companions. However, they are soon killed by a mysterious assassin...
Subaru discovers that when he dies, he wakes up at the same point where he was teleported to relive his day. But will his ability to go back in time be enough to avoid all the tragic events that will befall him?