Sixteen sentient races inhabit Disboard, a world overseen by Tet, the One True God. The lowest of the sixteen—Imanity—consists of humans, a race with no affinity for magic. In a place where everything is decided through simple games, humankind seems to have no way out of their predicament—but the arrival of two outsiders poses a change. On Earth, stepsiblings Sora and Shiro are two inseparable shut-ins who dominate various online games under the username Blank. While notorious on the internet, the pair believe that life is merely another dull game. However, after responding to a message from an unknown user, they are suddenly transported to Disboard. The mysterious sender turns out to be Tet, who informs them about the world's absolute rules. After Tet leaves, Sora and Shiro begin their search for more information and a place to stay, taking them to Elkia—Imanity's only remaining kingdom. There, the duo encounters Stephanie Dola, an emotional girl vying for the kingdom's sovereignty. In desperation, she attempts to regain her father's throne, but her foolhardiness makes her goal unachievable. Inspired by the girl's motivation and passion, Sora and Shiro decide to aid Stephanie in getting Elkia back on its feet, ultimately aiming to become the new rulers of the enigmatic realm.

The rare and inexplicable Puberty Syndrome is thought of as a myth. It is a rare disease which only affects teenagers, and its symptoms are so supernatural that hardly anyone recognizes it as a legitimate occurrence. However, high school student Sakuta Azusagawa knows from personal experience that it is very much real, and happens to be quite prevalent in his school. Mai Sakurajima is a third-year high school student who gained fame in her youth as a child actress, but recently halted her promising career for reasons unknown to the public. With an air of unapproachability, she is well known throughout the school, but none dare interact with her—that is until Sakuta sees her wandering the library in a bunny girl costume. Despite the getup, no one seems to notice her, and after confronting her, he realizes that she is another victim of Puberty Syndrome. As Sakuta tries to help Mai through her predicament, his actions bring him into contact with more girls afflicted with the elusive disease.

Jinta Yadomi is peacefully living as a recluse, spending his days away from school and playing video games at home instead. One hot summer day, his childhood friend, Meiko Menma Honma, appears and pesters him to grant a forgotten wish. He pays her no mind, which annoys her, but he doesn't really care. After all, Menma already died years ago. At first, Jinta thinks that he is merely hallucinating due to the summer heat, but he is later on convinced that what he sees truly is the ghost of Menma. Jinta and his group of childhood friends grew apart after her untimely death, but they are drawn together once more as they try to lay Menma's spirit to rest. Re-living their pain and guilt, will they be able to find the strength to help not only Menma move on—but themselves as well?

Striking fear into the hearts of mortals, the Demon Lord Satan begins to conquer the land of Ente Isla with his vast demon armies. However, while embarking on this brutal quest to take over the continent, his efforts are foiled by the hero Emilia, forcing Satan to make his swift retreat through a dimensional portal only to land in the human world. Along with his loyal general Alsiel, the demon finds himself stranded in modern-day Tokyo and vows to return and complete his subjugation of Ente Isla—that is, if they can find a way back! Powerless in a world without magic, Satan assumes the guise of a human named Sadao Maou and begins working at MgRonald's—a local fast-food restaurant—to make ends meet. He soon realizes that his goal of conquering Ente Isla is just not enough as he grows determined to climb the corporate ladder and become the ruler of Earth, one satisfied customer at a time! Whether it's part-time work, household chores, or simply trying to pay the rent on time, Hataraku Maou-sama! presents a hilarious view of the most mundane aspects of everyday life, all through the eyes of a hapless demon lord.