Kakyu a former Japanese who was reincarnated as a lowlevel demon in hell has acquired unparalleled strength over two thousand years However unexpectedly he is exiled to another different world liberated from the harsh underworld Kakyu who was enjoying his dream slow life witnesses the village he owes everything to being attacked Despite rushing to the scene the village is annihilated Picking up the only surviving baby Alus Kakyu resolves to raise Alus to become the happiest person in the world to repay the debt