Keita Amano is a typical high school gamer living out an average student's life. One day, however, he has an unexpected meeting with the cutest girl in school that makes him want to disappear without a trace! This girl, Karen Tendou, is an exemplary student who is proclaimed to be the school's idol. She discovers that Amano is a gamer, and this newfound knowledge incites a passionate desire within her to recruit him into the game club. Upon visiting the club, Amano is forcefully made aware of a side to gaming wildly different than the one he loves so dearly. Tendou's interest in Amano begins shaking up what was once an uneventful life, filling it with spontaneity, awkwardness, and a little bit of mayhem. As a result, every day becomes a comical battle for Amano's sanity as he tries to adapt to these wild, unexpected changes.

Nichijou primarily focuses on the daily antics of a trio of childhood friends—high school girls Mio Naganohara, Yuuko Aioi and Mai Minakami—whose stories soon intertwine with the young genius Hakase Shinonome, her robot caretaker Nano, and their talking cat Sakamoto. With every passing day, the lives of these six, as well as of the many people around them, experience both the calms of normal life and the insanity of the absurd. Walking to school, being bitten by a talking crow, spending time with friends, and watching the principal suplex a deer: they are all in a day's work in the extraordinary everyday lives of those in Nichijou.

There is a popular saying: you can never be too careful. It is very important to prepare for every situation you may face, even if it seems like an unnecessary waste of time. Also, in games like RPGs, it is good to exceed the level of your enemies to achieve total victory. These words describe Seiya Ryuuguuin a little too perfectly. After being summoned by the goddess Ristarte to save the world of Gaeabrande from destruction, the hero prepares himself for his noble journey. While this might be normal, he spends a very long time training himself, despite having overpowered stats. He fights weak enemies using his strongest skills and buys excessive amounts of supplies and potions—all to stay safe. While his attitude may be a bit annoying, it might just be the saving grace of Gaeabrande, especially considering that it is a world where the forces of evil dominate each and every expectation.

For as long as he can remember, Minoru Kagenou has been fixated on becoming as strong as possible, which has led him to undertake all kinds of rigorous training. This wish, however, does not stem from a desire to be recognized by others; rather, Minoru does everything he can to blend in with the crowd. So, while pretending to be a completely average student during the day, he arms himself with a crowbar and ruthlessly thrashes local biker gangs at night. Yet when Minoru finds himself in a truck accident, his ambitions seemingly come to a sudden end. In his final moments, he laments his powerlessness—no matter how much he trained, there was nothing he could do to overcome his human limitations. But instead of dying, Minoru reawakens as Cid, the second child of the noble Kagenou family, in another world—one where magic is commonplace. With the power he so desired finally within his grasp, he dons the moniker Shadow and establishes Shadow Garden: a group whose sole purpose is to combat the enigmatic Cult of Diablos, an organization born from Cid's imagination. However, as Shadow Garden grows in both membership and influence, it becomes increasingly apparent that the Cult of Diablos is not as fictional as Cid had intended.