That time I was reincarnated as a slime It has an immersive universe filled with many fan-favorite fantasy elements and themes. The anime is set in Central World, where the protagonist Rimuru Tempest has adapted to a new world that is very different from the ordinary world he used to live in. This world contains a type of magical element that is similar to the particles that make up most matter and is the core of most magic. The importance of magic cannot be overstated, as it is the main component and sustenance of monsters. Furthermore, magic can be used in unimaginable ways, with the limitations of its use mostly being the imagination and ingenuity of the individual.