After the defeat of the demon lord Hadlar all of the monsters were unleashed from his evil will and moved to the island of Delmurin to live in peace. Dai is the only human living on the island. Having been raised by the kindly monster Brass, Dai's dream is to grow up to be a hero. He gets to become one when Hadlar is resurrected and the previous hero, Avan, comes to train Dai to help in the battle. But Hadlar, announcing that he now works for an even more powerful demon lord, comes to kill Avan. To save his students Avan uses a Self-Sacrifice spell to attack, but is unable to defeat Hadlar. When it seems that Dai and Avan's other student Pop are doomed a mark appears on Dai's forehead and he suddenly gains super powers and is able to fend off Hadlar. The two students then go off on a journey to avenge Avan and bring peace back to the world. (Source: Anime News Network) *Notes: Chapter count includes the respectively two and three chapter short stories "Derupa! Iruiru!" and "Dai Bakuhatsu!!" which were published in earlier Weekly Shonen Jumps pre-serialization and collected in the volumes.*

It's the Century of Darkness where monsters known as Vandels rule the world, and the Vandel Busters are the only ones who can fight them. When a group of Busters are killed in battle, they pass on their magic Saiga weapons to Beet, making him the strongest Buster ever. But Beet won't just fight the Vandels--he wants to destroy them and finally end the Century of Darkness. (Source: VIZ Media)

In Poland, a country powered by steam, the new technology was also applied to combat. Wearing steam armor, warriors compete in martial arts tournaments to fight for the title of "Knight King," a badge of strength. A young girl named Łucja joined the tournament, wielding two arms of steam armor. The difference between Łucja and the other fighters is that Łucja is otherwise unarmed, using only her fists and the strength of her single blow to defeat her opponents. (Source: Comic Border, translated) *Note: includes 3 bonus chapters in Vol. 3.*

After the liberation of Papnica, Dai was asked by a certain boy to become his apprentice. After a few days of training, he heard rumors that there was a hero who learned Avan-style techniques, so he went to meet him hoping to learn and become stronger. Dai struggled under the guidance of an unfamiliar "master'', but...!?

The protagonists of this work, Gin and Prana, earn their living. They are warriors who live off the rewards of defeating monsters.