Shizuku and the other students return to the royal capital. Their brush with death, and the dramatic reencounter with Hajime Nagumo, has had different effects on each student's mind. Hajime, now joined by Kaori, arrives at the Gruen Desert.

Hajime's party reaches Ankaji. Hajime must perform multiple miracles to save this dukedom from certain doom before traveling to his real destination, the Grand Gruen Volcano, the next labyrinth on his list.

Hajime completes the grueling trial at the end of the Grand Gruen Volcano labyrinth, but at that exact moment, Freid, a demon commander, launches a surprise attack. Hajime is heavily injured, and a desperate battle begins.

Tio escapes the volcano alone and flies towards Ankaji. Meanwhile, Hajime and the others, still in the volcano, hatch a plan to escape the incoming lava without sacrificing any of their goals.

Hajime and his party departs the city of Erisen to head towards the Sunken Ruins of Melusine. They solve multiple puzzles to reach the labyrinth, and are confronted by a mysterious illusion.

Hajime and Kaori, separated from the others, move deeper into the labyrinth. They encounter an even more disturbing illusion, but Kaori has more important concerns - does she really want to continue this relationship with Hajime?

Daisuke and his shadowy co-conspirator overtly take action against Commander Meld, triggering the final phase of their nefarious plan. Meanwhile, Hajime encounters a group of bandits attacking someone he has met before.

Hajime arrives at the Divine Mountain to rescue Aiko, but is immediately attacked by Noint. Meanwhile, a massive force of Demons and monsters suddenly appear just outside the capital city of Heiligh and immediately begin sieging the city.

As Hajime's deadly duel versus Noint continues, Aiko and Tio hatch a plan to assist Hajime. The other students also notice the alarming noise and gather together to figure out what's going on.

With her trap sprung and all of the students rendered unable to fight, Eri reveals her true nature and sets the rest of her plan in motion.

Hajime once again saved the day, thwarting Eri's evil plans and the demons' invasion. With the royal capital now safe, Hajime discusses future plans with his companions and classmates.