Rimuru and Veldora are slacking off as usual until they're interrupted by a sudden transportation into another world, where they meet velzard and velgrynd who were also transported there.

The world once knew peace - until the Gates appeared. At first, a single colossal stone gate rose in the heart of Japan, bridging reality with a fantasy realm. But the phenomenon did not stop there. Gates erupted across the globe, each one a doorway to distant worlds beyond imagination. From kingdoms of magic to realms of demons, from hunters of shadows to soldiers of steel, beings crossed freely without warning or restraint. Their arrival reshaped societies, twisted destinies, and unleashed powers that defied comprehension. Now, as worlds collide and boundaries shatter, alliances must be forged, battles must be fought, and the fate of countless realities hangs in the balance.

TENSURA MUSHOKU

Tres mundos han sido fusionados y solamente una persona, o más bien un slime es el único en percatarse. Mientras Rimuru trata de resolver este desastroso problema. Muchos desafíos empiezan a parecer, un hechicero con una mentalidad diferente a éste intenta Conquistar el mundo, y mientras que muchas personas tratan de sobrellevar el despertar de 10 seres malignos muy poderosos, Rimuru tendrá que evitar la catástrofe mientras vive los sucesos que le corresponden.