To investigate the dragon sighted in Azeshion, Anos and his friends visit the Hero Academy in the name of participating in an exchange program. Emilia teaches at the Hero Academy, but despite her efforts, Ledriano and the other students of the Hero Academy are rather unenthusiastic about the exchange. Furthermore, Zamira, the headmaster of the Hero Academy, issues a decree to slay the dragon. Yet, as Emilia resists his unreasonable order, the Hero Academy students begin to lose interest…

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.”

Ahide announces that Midhaze will be destroyed. However, the oracle’s will contradicts Arcana’s true intentions. Shin also joins in the fray as the two finally face off! Ahide possesses Arcana and thrusts the judgement of the Sword of the Almighty, Leviangilma, upon Anos. Arcana states that to destroy Ahide, he must be slashed three times with the Divine Sword. But the sword obliterates the source of anyone who draws the sword from its sheath….

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!?

Arriving in Giorhaze, capital of the Underground World Giordal, Anos follows a wary Erdomaid to a church. There, they obtain a Pledge Jewel which summons dragons. Furthermore, Erdomaid sees Naya’s aptitude and makes a pack with her after learning her plan. Anos hears about Ahide’s actions from the bishop of the church and decides to catch him before he meets the pope.

The sacred Sojourner’s Psalm to be performed at the Divine Dragon Festival is in danger of being cancelled due to Ahide’s schemes! Ellen and the Anos Fan Union are asked to take the stage instead as the Dilhade Demon King Choir. The Draconids are drawn in by their song and begin to sing along. Meanwhile, while trying to pursue and capture Ahide, Anos encounters Dietrich, the King of Agatha, who has received a prophecy from the Goddess of the Future Naphta.

Anos and Pope Golroana clash for the future of their respective countries! GGG launches a fierce attack with Gospel Magic using the power of the God of Gospel Doldread, who controls sound. Anos counters with the song of the Dilhade Demon King Choir and brings Golroana’s support, the former popes, into the fray. Yet even after the conclusion of the battle, Golroana continues his prayers. Anos offers him peace, but…

Ceris, commander of the Phantom Knights, who claims to be Anos' father, says that Militia gave Anos false memories. After Ceris leaves, Arcana, unable to recover her memories of Anos, falls into a dream once again. In her memory of 2,000 years ago, Arcana hears a secret about herself from Ceris. Anos reincarnates Arcana to protect her, but his wish for her at the time was…