Failure Frame: I Became the Strongest and Annihilated Everything with Low-Level Spells

On the way to the field trip, the Class C bus is suddenly enveloped in a white light: the teacher and students onboard have been summoned to another world by the goddess Vicious. She is meaning to raise them as heroes and defeat the Great Demon Emperor. The students are welcomed by the goddess with open arms as their abilities are assessed and sorted one by one with the goddess' crystals.

After defeating the demons of the Abandoned Ruins, Touka reawakens to his cruel side, which he had hidden deep inside. The usual Touka Mimori, who was treated like thin air in class, is nowhere to be found there. He raises his level while confirming the characteristics of his own Inherent Skill, "Abnormal State Endowment".

Touka has defeated the Soul Eater and escaped the Abandoned Ruins. What he obtained there are a huge amount of EXP, the book titled Forbidden Arts: The Complete Works left by Anglin, and Book of Forbidden Spells. He seeks vengeance against the Goddess Vicious. For that purpose, he tries to find the nearby city in hope of some information on this world.

Touka arrives in Mills City and participates in the Mills Historic Ruins raid organized by the local lord in order to try to strengthen his companion slime, which method was mentioned in the book Forbidden Arts: The Complete Works. There, he reunites with Mist, a woman who is also participating in the raid and trying to get the reward money, and asks her to help him prepare for his adventure.

After leaving Mills Ruins, Touka asks Mist, or rather, the high elf Seras Ashrain, who had been hiding her true identity, to escort him to the Golden Demon Zone. Seras gladly accepts his offer, and the two promise to meet up as soon as she finishes receiving hospitality from the lord for her effort.

It is Civit Garland, Humanity's Strongest, and his Five Dragon Knights, who are after Seras' soul. The one who asked them to annihilate Seras was Ortora, the Holy King of the Kingdom of Neia, to whom Seras had been loyal. Touka stands in front of Civit to save Seras, whose heart is also broken by this fact.

Seras vows to Touka that she will become his sword of revenge against the goddess Vicious. With Seras in tow, Touka proceeds to the capital city of Monroy in Urza, which is close to the Golden Demon Zone. There, the two hear of the rumors about Eve Speed, the strongest Blood Fighter in Monroy, who might know where the Forbidden Witch is.

Eve has been fighting as a Blood Fighter to gain freedom for herself and a girl. Tomorrow will be her final day in the arena. However, Zuan, who operates the Blood Colosseum, schemes to dispose of Eve in front of the public by using poison in order to create a new star fighter. Having caught wind of the rumor, Touka and Seras inform Eve of Zuan's plan to save her and the girl.

Zuan sends his private army and the sorcerer group, Ashinto as pursuers to capture Eve and Liz. Touka, employing his strategies, lies in wait for Ashinto within the forest. Muaji, the leader of Ashinto, who possesses keen insight and specializes in poison, quickly sees through Touka's plan. Calmly, Muaji begins to corner Seras.

At last, Touka and his friends arrive at the Golden Demon Zone, a dangerous zone where powerful demons are everywhere. While defeating the demons along the way, they proceed to the location of the Forbidden Witch. At that time, an egg Touka has obtained from the Skeleton King is about to hatch.

The screaming demon draws the humanoid demons within the Golden Demon Zone. In the midst of the desperate crisis, Touka tells Seras and the others how they can all survive. It is for him to take on all the demons by himself, which by itself is reckless already... Finally, the great stampede of demons hits Class 2-C, and several students are sacrificed in vain.

While searching for Touka, Eve encounters Kobato, alongside Hijiri and Itsuki, trying to save Kobato. Eve tries to leave the place in discretion so that Hijiri will not be aware of Touka's presence. Meanwhile, Touka, though wounded to the core, has dispelled almost all the demons. All that remains is the cunning humanoid that has been carefully observing the battle.