Using the mutant disturbance as a decoy the demon army advances on the Kingdom of Limia and the Empire of Gritonia. The hyuman army tries to intercept them, but are quickly outnumbered and overpowered. The two great powers are on the verge of collapse.

Tomoe, Mio, and the residents of the demiplane are ordered by Makoto to take back Kaleneon, and enter enemy territory. Meanwhile, in the Gritonia Empire, Tomoki and his friends head to the battlefield, where they encounter Sofia standing in their way.

Due to the incident with Zara, Makoto decides to join the demons, and after witnessing the fighting tournament, he decides to leave Rotsgard. The next day, Jin and his friends advance to the finals of the team competition and face a team led by Ilumgand.

Sofia suddenly barges into the battle between Makoto and Io. Having longed for a rematch with Makoto, Sofia launches a fierce attack on her nemesis as soon as she steps onto the battlefield. Despite being outnumbered, Makoto appears unfazed.

After the battle in Limia, Makoto returns to the demiplane where he is welcomed by Tomoe, Mio and the residents of the demiplane. After a short celebration Makoto returns to Rotsgard to wipe out the remaining mutants, ending the days-long turmoil.

In order to save Rembrandt's wife and children from the cursed disease afflicting them, Makoto and Hazal get to work producing the wondrous medicine known as ambrosia. After administering the medicine, Makoto prays for their recovery and leaves Rembrandt's mansion. Tomoe and Mio meet up with Makoto after he completes the job. They're attacked by a group of strangers who have been following them since they left the inn...

Makoto is shaken by the revelation that the hero he meets on the battlefield is his high school senior, Hibiki Otonashi. Unable to dwell on it, Makoto enters a battle with Io to whom he suggests the demons retreat, in order to avoid a pointless battle

Makoto and Mio visit Tinarak Forest in order to acquire ambrosia flowers for the Kuzunoha Trading Company, but they are attacked by Aqua and Eris, the forest ogres protecting the flowers. Distracted by a deranged Mio and the adventurers who happened to show up, Makoto finds himself cornered. With Tomoe's help, Makoto and Mio escape their predicament. However, at the forest ogre village they visited to negotiate a deal, they get dragged into yet another incident...

Students take on the individual competition in the school festival's highlight event, the combat tournament. Due to a nobleman plot, they are forced to face off against their peers. Jin advances to the finals and faces off against Ilumgand Hopleys.

Ilumgand was transformed into a monster. Jin and Abelia launch an attack to stop him. However, their attacks have no effect, and they lose their fighting spirit and energy in the face of an enemy stronger than ever.

Rotsgard's turmoil continues. Numerous mutants have appeared in the city and Jin and his friends attempt to subjugate them. Meanwhile, Mio, who has been ordered by Makoto to protect the shelter, detects a strange smell from Makoto during her mission.

The mutant turmoil shows no signs of ending. At the evacuation center, people who've transformed into new mutants have appeared, anxiety and fatigue have reached their peak. To change the situation, Misumi's group joins the mutant subjugation force.

Outside Limia's royal castle, a fierce battle between Shiki and Mitsurugi unfolds. Meanwhile, inside the castle, the battle between Makoto and Sofia continues. Sofia, at a loss, unleashes her secret weapon.

Makoto's party accepts the Rembrandt Trading Company job. They've already acquired the necessary materials, and their first job as adventurers seems to be going well... But trading company owner Patrick Rembrandt distrusts Makoto, as he lacks any kind of adventuring record. Furthermore, Makoto seeks to join the merchants' guild, where two tests await him.

Having completed the job for Rembrandt, Makoto is relaxing in the demiplane, but there's a new problem. The Highland orc and lizardmen warriors Makoto and his companions have been training have lost their confidence. Tomoe announces the Demiplane Ranking, a series of one-on-one combats between warriors of all species in order to raise their morale!

Makoto attends a luncheon on the second day of the festival and is approached by Sairitsu, an official with the Laurel Commonwealth. She suspects Makoto may be from another world because of the foreign characters on the Kuzunoha Trading Company's sign.

A feast is held to celebrate the establishment of Kuzunoha Trading Company in the hyuman town. After getting better acquainted with the residents of the demiplane, Makoto sneaks off to practice archery. However, a very flustered Tomoe and Mio show up. Mio suddenly bursts into tears, and Makoto struggles to understand the situation. Just then, Tomoe says something unbelievable!

A mysterious explosion occurs in the demiplane, and Tomoe collapses. Though Makoto is unsettled by the sudden events, he heads to the site of the explosion in order to treat the wounded. Makoto is shocked to learn the denizens of the demiplane were harmed in the explosion. Meanwhile, he learns the truth from the hyuman memory that enters his mind! What will Makoto do once he discovers the selfish actions they took?!

Makoto departs for the academy... at least, that was the plan. However, the goddess transports Makoto into the middle of a battle between hyumans and demons. There he is attacked by the strongest hyuman adventurer Sofia Bulga and greater dragon Mitsurugi. Having sided with the demons, Sofia and Mitsurugi believe Makoto is the goddess' disciple and attack mercilessly. Facing a crisis, Makoto musters the last strength he has remaining and activates his magic--

We meet one of Misumi Makoto's classmates back on earth, who also has a curious encounter with a certain goddess who presides over a certain isekai. She and one other are sent there as heroes to help the hyumans defeat the demons.

Lime sets out to investigate hyuman experiments that are secretly being carried out in Rotsgard. He ends up being captured by an underground organization along with Eva. After that, the two manage to escape and meet up with Shin and the others.

One day near summer's end, the highland orcs are attacked by wolves and bears while exploring the forest. After hearing the news, Makoto goes to the forest in an attempt to make peace between them, but the bear he meets looks upon him with hostility.

The academy festival is fast approaching. Shinai, a temple priest, arranges a meeting with Makoto on short notice. Shinai informs Makoto about rumors concerning the medicine being sold at the shop and offers Makoto a proposal to help dispel them.

Makoto leaves behind the destroyed town of Zetsuya and travels towards a new town with Toa, Rinon, and other adventurers. While defeating many monsters on the road, the group safely arrives in Tsige. Sorry to see Toa and her party go, Makoto suggests they throw one last party. During the party, Makoto hears an unsettling rumor about the Rembrandt Trading Company, the client of his first job...

Hibiki and Tomoki's parties prepare for the attack on Fort Stella (the one Makoto ended up being somewhat involved in against his will). The two human heroes couldn't be more different, posing challenges beyond the simple difficulty of facing the demons.