Thanks to the Fruit of Evolution, Seiichi Hiiragi's amazing new life in another world allows him to meet dependable allies and create formidable spells. His abilities catch the attention of Barnabus Ablitt, the principal of the Barbador Academy of Magic, who invites Seiichi to become a teacher at the institution. Coincidentally, Seiichi's classmates from Earth are enrolled there, which will lead to an awkward reunion if he is to meet them. Behind the scenes, however, an enigmatic cult called The Great Devil Order devises a sinister scheme to resurrect their deity and sacrifice the students of Barbador to hasten the process. As Seiichi's power is second to none, it is up to him to protect not only his friends but also the entire world from the looming darkness.

On a rainy afternoon, a male high school student awakens freezing on the streets with no memory of how he got there. His classmate and crush, Karen Inukai, finds him and takes him back to her home where, to his surprise, she starts to undress. She seems intent on bathing with him, though he has no idea why. When she holds him once more, he catches a glimpse of himself in the mirror—discovering that he has turned into a dog! Inukai adopts the puppy and names him Pochita. Now, he must adjust to life as a dog and figure out how to get out of this strange predicament. But while he mulls over an escape plan, Pochita sees a whole new side to Inukai that he never saw at school.

On the planet Noman's Land, reporters Meryl Stryfe and Roberto De Niro traverse the desert in search of the infamous outlaw Vash the Stampede. But the man they find near the desolate town of Jeneora Rock is a far cry from the lethal terrorist they expect. In reality, Vash is a passive and carefree drifter; he is a proponent of peace, beloved by the residents of the town. His inaccurate reputation actually stems from the widespread atrocities committed by his twin brother Knives Millions. Still, Vash is dubbed "The Humanoid Typhoon'' due to the tendency for violent chaos to follow in his wake. Chaos soon arrives in the form of bounty hunters seeking the high price on Vash's head, and their violent pursuit poses great danger to the town and its precious power plant. Thanks to his gunslinging prowess, Vash is able to resist most of these nefarious forces. Yet he must soon face off against the ultimate evil: the unstoppable destructive power of his malevolent brother.

Veteran adventurer Nick, mage Tiana, cleric Zem, and half-dragon Curran each show up alone at a tavern, only to find themselves seated at the same table. As the night goes on, they take turns divulging their grievances and the hobbies they have taken up as a means of coping. While their stories are utterly different, there is one common thread: betrayal. Each of the four, having been bitterly betrayed by someone they treasured, has developed a deep-seated distrust of humanity. But in addition to their similar worldviews, the four have one more commonality: a critical lack of funds. Realizing that things cannot continue as they are, they decide to form a party, rank up, and make as much money as possible to spend on their respective hobbies. What these disillusioned adventurers do not know, however, is that they will one day save the world from unfathomable peril.