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.

In the year 2010, the Holy Empire of Britannia is establishing itself as a dominant military nation, starting with the conquest of Japan. Renamed to Area 11 after its swift defeat, Japan has seen significant resistance against these tyrants in an attempt to regain independence. Lelouch Lamperouge, a Britannian student, unfortunately finds himself caught in a crossfire between the Britannian and the Area 11 rebel armed forces. He is able to escape, however, thanks to the timely appearance of a mysterious girl named C.C., who bestows upon him Geass, the Power of Kings. Realizing the vast potential of his newfound power of absolute obedience, Lelouch embarks upon a perilous journey as the masked vigilante known as Zero, leading a merciless onslaught against Britannia in order to get revenge once and for all.

One year has passed since the Black Rebellion, a failed uprising against the Holy Britannian Empire led by the masked vigilante Zero, who is now missing. At a loss without their revolutionary leader, Area 11's resistance group—the Black Knights—find themselves too powerless to combat the brutality inflicted upon the Elevens by Britannia, which has increased significantly in order to crush any hope of a future revolt. Lelouch Lamperouge, having lost all memory of his double life, is living peacefully alongside his friends as a high school student at Ashford Academy. His former partner C.C., unable to accept this turn of events, takes it upon herself to remind him of his past purpose, hoping that the mastermind Zero will rise once again to finish what he started, in this thrilling conclusion to the series.

Asta and Yuno were abandoned at the same church on the same day. Raised together as children, they came to know of the Wizard King—a title given to the strongest mage in the kingdom—and promised that they would compete against each other for the position of the next Wizard King. However, as they grew up, the stark difference between them became evident. While Yuno is able to wield magic with amazing power and control, Asta cannot use magic at all and desperately tries to awaken his powers by training physically. When they reach the age of 15, Yuno is bestowed a spectacular Grimoire with a four-leaf clover, while Asta receives nothing. However, soon after, Yuno is attacked by a person named Lebuty, whose main purpose is to obtain Yuno's Grimoire. Asta tries to fight Lebuty, but he is outmatched. Though without hope and on the brink of defeat, he finds the strength to continue when he hears Yuno's voice. Unleashing his inner emotions in a rage, Asta receives a five-leaf clover Grimoire, a Black Clover giving him enough power to defeat Lebuty. A few days later, the two friends head out into the world, both seeking the same goal—to become the Wizard King!