Isekai (Japanese: 異世界 transl. 'different world', 'another world', or 'other world') is a sub-genre of fiction. It includes novels, light novels, films, manga, anime, and video games that revolve around a displaced person or people who are transported to and have to survive in another world such as a fantasy world, game world, or parallel universe with or without the possibility of returning to their original world. Isekai is one of the most popular genres of anime, and isekai stories share many common tropes – for example, a powerful protagonist who is able to beat most people in the other world by fighting. This plot device typically allows the audience to learn about the new world at the same pace as the protagonist over the course of their quest or lifetime. If the main characters are transported to a game-like world, the genre can overlap with LitRPG. The concept of isekai started in Japanese folktales, such as Urashima Tarō. However, the first modern isekai works were Haruka Takachiho's novel Warrior from Another World and Yoshiyuki Tomino's television series Aura Battler Dunbine. Source: Wikipedia (en)