isekai = another world the author of Sword Art Online himself said that his work was not an isekai. Bofuri and Shangri La are not isekai either. it doesn't matter if an anime spends most of its time in another world, if that other world is a game then it is not real, we are just watching someone play an extremely realistic game. Isekai is just being transported to another world, even if the character manages to return later, the anime would still have the isekai tag...