Similar to the movie industry, the world of anime also consists of sequels, spin-offs, and prequels. Unlike Hollywood, which mainly makes sequels to capitalize on a successful IP, anime series have lots of sequels because their source material—mainly manga and light novels—has lots of content that can still be adapted. As such, if the studio wants to deliver a complete story to the fans, they have to adapt the whole thing, which may take several seasons to do.