Satoru Mikami, a thirty-seven-year-old office worker, is stabbed to death on a Tokyo street and wakes up in a fantasy world reborn as a weak slime. The body comes with two gifts: Predator, which lets him absorb anything he eats and copy its abilities, and Great Sage, an analytical voice that guides him. After freeing the sealed storm dragon Veldora and taking the name Rimuru Tempest, he sets out to build a place where monsters and other races can live together.