Subaru Natsuki is your typical NEET who just likes to play games. He was unexpectedly called to another world one night after leaving a store. Without knowing who called him, he soon became acquainted with a girl with medium silver hair who introduced herself as Satella and her friend Puck. Satella states that her badge had been stolen by a criminal who later appeared to be named Felt. When he and “Satella” are mysteriously killed, Subaru wakes up to discover that he has gained an ability called “Return by Death” that helps him to turn the clock back by death. He welcomes “Satella” again, only to insult her by giving her the word “Satella” which literally means “witch of envy” and is taboo. In order for Subaru to save “Satella” from the assassin Elsa, he requested help from a knight named Reinhard. Later on, “Satella” told her real name was Emilia before Subaru collapsed from blood loss. In thanks, Felt returned the badge. In doing so, though, Reinhard spotted the shimmering badge on Felt’s palm and picked it up and said it was a sin to neglect it.
After he recovered and woke up in the Marquis Villa of Roswaal, the spirit of Beatrice drained Subaru’s mana. When Subaru woke up, he is greeted by lovely twins Ram and Rem. He also meets Roswaal and asked if he could be hired as a butler. Roswaal has announced that Emilia requires a badge to register as a candidate for the forthcoming royal election. After Subaru mysteriously dies again, he decides to investigate the circumstances that lead to his death and to attempt to reconstruct those events. After a series of horrific deaths and resurrections, he learns that he was cursed and then believes that he came from a village he had visited earlier, while at the same time releasing Rem’s deep distrust of the witches. Eventually, the village was threatened by beings known as Mabeasts, animal demons who were allegedly formed by a wizard to kill mankind. Subaru, Rem, and Ram had to save the villages.
Emilia was then called to the capital by two veterans of the Crush camp, Wilhelm and Felix, who were both parts of the royal guard at the beginning of the election of the king. At that time Subaru’s group have met with other royal contenders: Priscilla, Crusch, Anastasia, and Felt; including the knights Aldebaran, Julius, and Reinhard. Felt originally declared that she was not going to run for the election, and Subaru said that he was Emilia’s knight. After a public fight with Julius, who had critically wounded him, he got into a fight with Emilia and wanted to break off the Subaru link. He had been left behind.
Subaru decides to study under Wilhelm following his recovery, while Felix encourages him to pursue Emilia. Then Rem alerts Subaru that something is going on at the mansion, and Subaru agrees to go back to the mansion against Crusch and Felix’s warnings. There he found a number of bodies, including those of Rem, whom he dreaded. After he died and reappeared, he was ambushed by a wicked group named the Witch Cult, and he encountered the insane leader Petelgeuse, who oppressed Subaru, and Rem with a talent called the Invisible Hand. Then he was killed by an awful puck, and Subaru reappeared and cursed Petelgeuse.
Knowing that the mansion and the village are under attack, Subaru recruits the help of the other royal contestants, but they all refuse. When trying to develop an evacuation plan, he meets a mythical animal, the White Whale. When encountered by the White Whale, In order for Subaru to escape Rem chose to sacrifice herself. Subaru returned to the mansion and has met with Ram and Emilia but they do not remember Rem. Worried about the situation, Subaru admits to Emilia that he is willing to “come back through death” only to find out that she will die afterward. Shocked by what had just happened, Subaru asks Beatrice to kill him. Beatrice angrily refused to kill him and asked him to go somewhere where she can’t see him. Puck was furious at Petelgeuse and transformed to kill him and his cult. Puck also froze Subaru to death for failing to protect Emilia. Upon his return, Subaru, who is completely desperate, has a serious chat with Rem and begs her to run away with him. However, Rem clearly urges Subaru not to give up and confesses her affection for him because she already realizes that his heart is with Emilia. Subaru decides to resume all over again with fresh resolve.
Subaru has successfully forged an alliance with the Crusch and Anastasia camp in order to fight the White Whale. After the long fight with the White Whale, Wilhelm has managed to kill the White Whale and avenged the death of his wife. By forming new allies, Subaru finally defeats Petelgeuse and his cult. Subaru managed to save Emilia and the villagers. After the fight, Subaru confessed to Emilia and she smiled tearfully while thanking him for saving her. But when Subaru asked about Rem, Emilia still does not recall Rem for the second time which surprised him.