Seventeen-year-old Haruki Hoshino is a mixed martial artist who gets a bad reputation in high school because everyone thinks he is a delinquent. But his school life is over when he, along with his classmates, gets transported into another world as powerful heroes. But things take a turn for the worse. While Haruki gets summoned to the side of humans, elves, dwarves, and fauna-folks, his classmates get summoned to the side of demons and goblins. As the demons and goblins use Haruki's classmates to conquer the world, Haruki must save everyone as the Solaris Hero.