Re: Zero kara Hajimeru Isekai Seikatsu is a popular anime series that follows the story of Subaru Natsuki, a young man who is transported to a fantasy world. In this new realm, he discovers he has the ability to return from death, which he uses to unravel the mysteries of the world and protect those he cares about. The series is known for its intense emotional depth and exploration of themes like perseverance and sacrifice.