"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.

Misha confesses the shocking truth that, "At midnight on my 15th birthday, I’m going to disappear." Misha was never supposed to exist in this world in the first place, but due to Ivis Necron’s magic, she was living a transient life. She had resigned to her fate that she will only live for 15 years, but Anos tells her, "There are two things that I do not understand. Regret and saying that something is impossible." The misfit crushes the tragedy and unjust fate that binds the two sisters.

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?

Round 2 of the inter-academy exams begins. After Revest’s deplorable defeat against Heine, Anos and his team battle with the students of the Hero Academy. Anos says that he will think of a strategy if it becomes necessary, and clashes head-on with his enemies using his vast Magic Powers. However, due to a magic barrier called De Igelia that is cast over the entire city, and a young girl named Zeshia who wields the holy sword Enhale, Anos’ attacks prove to be futile. Anos and his team are unable to come up with their next strategy, but Misha proposes a plan that could help them win.

Everything started two thousand years ago. The situation suddenly shifts when the true identity of the man in the black mask, Avos Dilhevia, is revealed. Even after two thousand years, the wounds caused by the endless conflict between demons and humans have not been healed. The Demon King of Tyranny, Anos Voldigoad, makes a choice…

Erdomaid DittiJohn, one of the four evil royals, has appeared before Anos as a teacher at Demon King Academy. Not only that, he claims himself to be the Heavenly Father God NousGalia, and that the new "Child of God" who will vanquish the Demon King of Tyranny is also at the Demon King Academy. The “Misfit” who overcomes all odds sets off to a new battle!

Anos and his classmates search around Demon King Academy for the “Child of God.” While Anos’ comrades are fending off the attacks from the demons of two thousand years ago, Anos himself faces the King of Death’s Army Officer, Ziek Ozma, in a duel of intellect. In this duel, Anos must speculate who the “Child of God” is and make the correct guess. However, the number of times he can make his guess is limited.

What was Anos’ answer, and what is Ziek’s motive ― ?!

Anos and the first-year students visit Zehenburg under the guise of an expeditionary examination. Anos's goal is to find his former right-hand man, Shin Reglia, who left a message for him, "Wait for me in the Spirit Forest Aharthern." On the way to the forest, Anos meets an information broker, Lena. Together with her, who is also heading to Aharthern, the group proceeds into the forest's depths.

In order to visit the Spirit King, Anos and his team continue to go through trials provided by the Great Tree Spirit Enyunien. The next trial, “The staircase of Geunier” is a trial where they must choose the 5 correct paths out of the 20 paths before them, which appears to be a game entirely dependent on luck. However, thanks to the advice from Lena, Anos and the team individually made their ways to the top. Lay and Misa arrive to the Spirit King’s castle first, and engage in the final trial!

The Forest of the Great Spirit Aharthern. Anos who has transformed into his younger form, takes on the fake name Anoshu Polticoal, and decides to stay to investigate for a while. They watch over Shin who was tasked with being a bodyguard of the Great Spirit Leno by Anos prior to his reincarnation, and then appears the Blaze Death King Erdomaid, who claims to have brought information regarding the gods...

To prevent a clash that may happen between Anos and humans 2,000 years in the future, Hero Kanon proceeds with the plan to become an imposter Demon King himself, with Shin agreeing to this decision. Gradually but surely, Shin begins to change, and Leno realizes that she loves him. However, after fulfilling his duty to protect her, Shin begins to leave her side...

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!

Avos Dilhevia takes control over Magic Sword of Destruction Venuzdnor at last. Anos gives a calm smile to the enemy who seizes everything from the Demon King of Tyranny and reigns control, however... The true purpose of Avos taking control over the Magic Sword at the end of the fierce battle is revealed. How does Anos face off against the Child of God, destroyer of the Demon King of Tyranny, and the power that destroys all life!?

Erdomaid trains the students in methods of dragon slaying. He does so in a dangerous battle with an actual dragon summoned. Anos and his friends infiltrate the dragon’s den and arrive in the Underground World, where the dragonfolk called Draconids live. Ahide, who attacked the previous evening, guides them to the Institute of the Gods, Everastanzetta. There, Anos is told how he has already been involved in the “Judgement Selection.”