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.

In the beginning, an "orb" is cast unto Earth. "It" can do two things: change into the form of the thing that stimulates "it"; and come back to life after death. "It" morphs from orb to rock, then to wolf, and finally to boy, but roams about like a newborn who knows nothing. As a boy, "it" becomes Fushi. Through encounters with human kindness, Fushi not only gains survival skills but grows as a "person". But his journey is darkened by the inexplicable and destructive enemy Nokker and cruel partings with the people he loves.

Fate/strange Fake centers around an imperfect copy of a Grail War based on the Third Holy Grail War in Fuyuki. Following the conclusion of the third Grail War, a US-based organization with magi distinct from the London-based Mage Association, used data from Fuyuki's Grail War to plan their own ritual. Seventy years later, they used the city of Snowfield as the Sacred Land for their own Grail War. However, they were unable to successfully replicate every aspect of the ritual, resulting in it acting only as an imitation that has lost the Saber class and allowed for the summoning of strange Servants due to the blurring of the definition of a "hero." Rohngall and his pupil, Faldeus, have been dispatched by the Mage's Association to investigate the city and the state of the war. Faldeus, a US organization spy, has Rohngall sniped upon his arrival, despite knowing that Rohngall is a puppet. He declares that their Holy Grail War has been in development and is real, causing a commotion at the Clock Tower, and that he wishes to "advertise" the project to the Association.

By the mid-21st century, Tokyo's criminal underworld is ruled by Demon Lords—crime bosses who have undergone ether enhancement surgery, granting them terrifying superpowers. The only ones who can take them down are Heroes, bounty hunters who boost their own ether powers using the drug E3 (E-Three). With legalized killing as part of the job, being a Hero is less about justice and more about survival. Yashiro, known as the Reaper, is one such Hero—an independent enforcer who works alone. That is, until Jougamine, a high school girl and self-proclaimed "apprentice," forces her way into his life. Reluctantly taking her under his wing, Yashiro soon finds himself caught in a whirlwind of deadly conflicts.