Kazuma Satou, former NEET and current reincarnated adventurer, finally returns home after the incident at the Crimson Demon village. He is joined by his ever-reliable companions: self-absorbed goddess Aqua, one-trick pony arch-wizard Megumin, and masochistic crusader Lalatina Ford "Darkness" Dustiness. Following their recent exploits, the party is one step closer to vanquishing the Demon King and his armies—a terrifying task that Kazuma is eager to ignore for as long as possible. Things, however, are not going as smoothly as the group would like; they are constantly racking up debt, getting sidetracked during missions, and falling into traps due to their recklessness and eccentricities. As the party struggles with their perennial issues, they receive an invitation from a princess interested in hearing tales of the group's "heroic" deeds. Darkness' pleas to refuse the invitation only fire the others up to accept it, marking the start of yet another uncanny adventure with unforeseen consequences.

Sousuke Kaburaya, an impoverished detective, meets Sara, a princess from another world with magical powers. They start living together, and Sara quickly adjusts her life to modern Japan.

After passing away, a Japanese office worker finds himself reincarnated in another world as Ars, the newborn son of the noble Louvent family. The Summerforth Empire, where the Louvents rule over a small territory of a few thousand people, is a medieval-like land plagued by social inequality and political instability. As Ars grows older and learns more and more about his new environment, he becomes convinced that war will soon erupt. Fortunately, though Ars was not blessed with unrivaled strength or extraordinary magical aptitude, he does possess Appraisal: a seemingly unique skill that allows him to instantly grasp someone's current abilities and latent talents merely by looking at them. In an effort to prepare his domain for the imminent strife, Ars resolves to enlist the most exceptional people he can find, paying no attention to superficial qualities like race or social status.

Kivotos is a federal megalopolis comprising thousands of schools and is led by the General Student Council (GSC), which acts as its governing body. Ironically, despite being an academy city, Kivotos is rife with gun violence, and all students wield firearms as part of their everyday lives. As if the crisis in Kivotos was not enough, the GSC president is nowhere to be found. Fortunately, before her sudden disappearance, the GSC president enlisted the help of Sensei—a teacher who is most likely the only one in Kivotos—to support students in their time of need. Sensei's first course of action is to assist Abydos High School, a once prestigious academy now with merely five students in attendance. These remaining students are doing everything they can to pay their academy's crippling debt of almost one billion yen.