Constant Magical Academy has a new transfer student named Keina Doronz. Not only does she have almost the same name as Akuto's friend Keena, but she also has an identical bird-shaped hairpiece -- the same one that Akuto bought for a crying girl when he was a child. Who's the real girl from his memory? To make things more confusing, this unknown girl is demanding that Akuto take her on a date! Hilarity and magic school shenanigans ensue when Keina joins Keena, Junko, Korone, and Fujiko as they circle around our favorite hapless Demon King, Akuto Sai.

The Earth has been destroyed by a meteor from outer space. In the afterlife, Akuto and the heroines find a recreation of the world as it was before he became demon king. However, in this world, Liradans do not exist, and the demon king is a distant memory. What is the true nature of the “story” invading peoples’ minds? The final chapter of the series approaches the truth...

Shocking truths are revealed now that Keena has become Empress. What is the Empire? What is the world? What secret power is given only to the royal family? A beautiful girl from the jungle and a prince from an undersea city both appear, staking claim to the throne, only for CIMO8's own plot to cross paths. When the Empire faces its greatest peril, Akuto's power is unleashed once more!

Akuto has awakened as the Demon King, and has declared that he will kill the gods. Now he faces thousands of troops, Eiko Teruya, and his friends, Junko and Hiroshi. Meanwhile, Keena may hold the key to the future of humanity itself.

Far in the future, Japan has become a land ruled by magic and those who wield it. Akuto Sai arrives at Constant Magical Academy--the most prestigious magic school in the world--for his first year of high school. The only student to pass the Academy's intense entrance exam, he has his sights set on become a High Priest, the most powerful and virtuous magician in the land. However, when he arrives at the Academy, his future occupation is prophesied to be... The Demon King?! Now Akuto is the number one target on campus, and he must navigate his way with the help of his friends--a troublesome delinquent, a beautiful observer android, an honor-bound class representative, and a mysterious girl from his past--through the seedy underbelly of the world's premier magic academy.

Marine’s use of the Faceless Power only worsens the war between the Empire and the Republic. But this was only the beginning of The One’s plan. Will Akuto’s rage at losing Junko be enough to save the world? What is this power that comes from outer space? And what is “The Fictional Nature of the World”?

 Empress Kazuko, after killing her sister 2V, is revealed to be the true villain. Using the power of Zero, the First Demon King, she intends to enslave humanity. In order to save everyone, Akuto knows that the line of Demon Kings must end — and for that to happen, both he and Zero must die. Will Akuto and Brave be able to defeat Kazuko and Zero? Will Junko, Keena, and the others survive this battle? And what does the member of CMID-8, "USD," have to do with all this? Read the epic climax of the war between Demon Kings!