Isekai is a subgenre of Japanese light novels, video games, manga, and anime where the protagonist gets transported to or reborn in another world. They're usually tasked with completing a specific mission during their time in this new world they've been forced into. In recent years, isekai's popularity has skyrocketed, resulting in several more isekai anime adaptations.
Source：https://www.cbr.com/best-isekai-anime-ranked/
