Kyou kara Maou! S01-S03

Yuri Shibuya lived a very ordinary life, but after he tried to save a classmate from a group of bullies and ended up getting flushed down a toilet, his life changed. Instead of getting seriously injured, he was pulled inside. After that, the only thing he realized was that he was in a world that vaguely resembled medieval Europe. And to make things even stranger, he was told that since he had black hair and eyes, he was a Maoist! Mao is the ruler of Mazoku, who have a rather tumultuous coexistence with humans in this world. Despite the fear beneath his skin, he is different from other rulers who have grown accustomed to them. He is kind, considerate, and believes in justice, and he has no intention of solving problems through violence. They don't want someone who would govern the country through war and conflict. Now, Yuri is trying to be a good Maoist and at the same time, he is trying to adapt himself to the customs and culture of this land, in a land where the tension between humans and Mazoku has reached its peak.