The story begins when the protagonist, a 14-year-old girl named Ai Ohto, hears a mysterious voice while walking around town late at night. It gives her an egg, and beckons to her: "If you wish to change the future, you need only choose now. Believe in yourself, and smash the egg."
A young witch, on her mandatory year of independent life, finds fitting into a new community difficult while she supports herself by running an air courier service.
37-year-old corporate worker Mikami Satoru is stabbed by a random killer, and is reborn to an alternate world. But he turns out to be reborn a slime! Thrown into this new world with the name Rimuru Tempest, he begins his quest to create a world that’s welcoming to all races. Broken free from ordinary, stale past life, his fresh adventure in a fantasy world as a slime monster with unique abilities begins.
Orphen is a powerful sorcerer who is notoriously lazy. Everything changes when he finds a way to save his sis, who was turned into a dragon during their days at magic academy. Betrayed by friends who refused to help, Orphen will stop at nothing to track her down, even if he has to go it alone.