Shin-Makoku

Yuri Shibuya is an ordinary Japanese high school student who tries to do what's right. One unfortunate day, he tries to protect a classmate from bullies. In response, they dunk Yuri in the toilet—and then something magical happens: he's literally sucked into another world.

He finds himself in the land of Shin-Makoku (the True Demon Kingdom), home to the Mazoku—human-like creatures possessing magical powers. Almost immediately, Yuri meets Conrad Weller, who saves him from the enraged king of another kingdom and takes him to Queen Cecilia, the kingdom's former ruler.

Cecilia explains that according to an ancient prophecy, the new Maou (demon king) must be dark-haired, wear dark clothes, and have dark eyes—a description that fits Yuri perfectly. So, unexpectedly, he becomes the new Maou. Yuri is shocked: he doesn't want to be king at all, especially in an alien world. In the finale, he is introduced to the court and his new responsibilities, and he tries to comprehend what's going on.

Yuri tries to get used to the castle and learn the local customs, but he repeatedly runs into trouble: Mazoku culture is structured completely differently from what he's used to. He's particularly irritated by Wolfram von Bielfeld, an arrogant, handsome knight who distrusts "the man" and openly disdains the newly crowned king.

And so comes the first dinner at the royal table. When Wolfram makes a taunting remark about Yuri's mother, Yuri slaps him in the heat of the moment. For a mazoku, this means one thing: a marriage proposal. An awkward situation, indeed.