"Listen up, my beloved descendants. Your founding ancestor has returned." The most powerful Demon King in history, Anos, known for his tyrannical rule 2000 years ago, has been reincarnated. Entrance exams are being held at the Demon King Academy where they train his descendants to be his successor and become Demon Lords. The entrance exam is a practical test where students must duel each other. Bored of the war-torn world of 2000 years ago, the tyrannical Demon King, Anos, appears on the scene.

"One last thing, I’m glad I got to meet you." Without being able to understand Sasha’s true intent behind these final words, much time has passed, and Ivis, one of the Seven Elder Demon Emperors, holds a special class at the Demon King Academy called the Great Magic Training. The Seven Elder Demon Emperors are seven demons that Anos, the founding ancestor, created from his own blood. Emilia implores Anos to act respectfully to Ivis, but without hesitation, he speaks to Ivis in a condescending tone.

Shortly after Anos’ encounter with Misha and Sasha as well as his battle with Ivis, a transfer student named Ray enters the Demon Academy. As the Master of Magic Sword and powerful enough to defeat the Seven Elder Demon Emperors, Ray makes it clear that he wants to join a team with a capable leader, and requests to join Anos’ team. However, Anos refuses and proposes to Ray that, "If you prove that you are worthy, I will allow you to become one of my followers." Ray decides to form his own team and battles head-to-head with Team Anos during the team competition exam.

Anos resolves to defeat the Royalists no matter what tricks they have up their sleeve. He uses the sword received from his father Gusta to fight in his first match in the Magic Sword Tournament. Meanwhile in the dressing room, Lay clutches his chest. Sensing that something is wrong with Lay, Anos speculates that somebody is controlling Lay and a hostage may be involved. Who is conspiring to control the Magic Sword Tournament from behind the scenes?

Anos and Lay battle head-to-head at the Dilhade Magic Sword Tournament finals. With Sheila being taken hostage, the two are unable to fight at their full potential and come to a decision. Just as the showdown reaches its climax, a huge Magic Circle appears in the arena. The scenery around Anos and Lay begins to distort, and they are taken into an alternate dimension. The mastermind behind the recent events finally reveals his true identity.

After the Magic Sword Tournament, Anos and the other students visit Azeshion in the Human Realm for an educational exchange with the Hero Academy. While they individually explore the city, Anos heads to the Hero Academy saying that he wants to research something. The academy is off-limits to outsiders, but without hesitation, he tries to make his way inside. Eleanor Bianca, a third-year student at the Hero Academy, appears before Anos and says, "You’ll be safe as long as you’re with me" with a mischievous smile. She acts as Anos’ guide inside the academy.

After witnessing Great Spirit Leno and Shin meet a tragic fate, Anos and his classmates return to Delsgade in the present day. There, persecution against those of mixed blood by Meleheyth and the demons whom Avos Deilhevia brainwashed was progressing. Anos holds them off and heads to the throne room. He faces off against Avos who attempts to steal Magic Sword of Destruction Venuzdnor!

The Mythical Age. In an effort to destroy the Moon of Creation, Anos meets the Goddess of Creation Militia and begins to interact with her. And now the present... Anos, who has made his identity as the Demon King of Tyranny known throughout the world, joins classes at Demon King Academy as the transfer student, Anoshu. To train even stronger demons, Erdomaid instates the Great Demon King Drills. As the first initiative, swordsmanship training under Shin begins!

That day, Anos had a dream about a time that he lived together with a young girl. The young girl is strangely also named Arcana…. Furthermore, the fact that the Draconids called the fusion of Sasha and Misha the Goddess of Absurdity, Genedonov, was also a problem. To investigate the piling mysteries, Anos decides to take a special class in the Underground World. And as a special lecturer, Anos teaches the student of Demon King Academy himself!?