Denji is robbed of a normal teenage life, left with nothing but his deadbeat father's overwhelming debt. His only companion is his pet, the chainsaw devil Pochita, with whom he slays devils for money that inevitably ends up in the yakuza's pockets. All Denji can do is dream of a good, simple life: one with delicious food and a beautiful girlfriend by his side. But an act of greedy betrayal by the yakuza leads to Denji's brutal, untimely death, crushing all hope of him ever achieving happiness. Remarkably, an old contract allows Pochita to merge with the deceased Denji and bestow devil powers on him, changing him into a hybrid able to transform his body parts into chainsaws. Because Denji's new abilities pose a significant risk to society, the Public Safety Bureau's elite devil hunter Makima takes him in, letting him live as long as he obeys her command. Guided by the promise of a content life alongside an attractive woman, Denji devotes everything and fights with all his might to make his naive dreams a reality.

The contrastingly cute dragon, Al, the first king-killer in the demon world, who has a full combat score but is ready to die and longs for a happy retirement, bumps into the cunning human magician Le Fei, and accidentally becomes a super dad who raises Le Fei's son Dino. Will Dino be an ordinary and happy child, or will he bravely pick up the Warrior's Holy Sword and face his own destiny...

I'm Rei Hitoma, a self-professed misanthrope thanks to some past trauma. Just when I thought my new teaching job in the mountains would provide a chill, rejuvenating environment, it turns out that this school is actually for demi-humans who want to become full-fledged human beings! There's a mermaid, a werewolf, a rabbit, and a bird...all of whom are now my charges. It's my duty to teach them about humankind—and maybe in the process, I'll learn a few things myself. This isn't an alternate world or a case of reincarnation. It's just the story of a teacher at a somewhat peculiar school, and his students who are striving to become human.

A decade ago, 450-year-old vampire Ranmaru Mori was saved from the brink of death by Rihito Tatsuno, a young and innocent boy. Ever since then, Ranmaru has been working at the Tatsuno family's bathhouse with a secret: he wants a taste of Rihito's virgin blood as soon as he turns 18. However, his plan is threatened when Rihito falls in love with a girl on his first day of high school. Jealous and scared that Rihito's pureness will be ruined, Ranmaru begins to lurk in the shadows to protect him from any harm. During his operation, the vampire must keep his real identity hidden and make sure his target's virginity remains unsullied.