Shibuya Yuuri was a typical fifteen-year-old boy until one day, when trying to stop a classmate from being bullied, he is flushed down a toilet! As he opens his eyes, Yuuri finds himself in a strange land. However, having mistaken it for a medieval theme park, he then gets the shock of his life when he is told that not only has he been transported to another world, but he is also their new king: the maoh. Adjusting to Yuuri's new country isn't as easy as it would seem, especially as he manages to accidentally propose to the previous maoh's son on his first night in the castle! Now, the idealistic Yuuri must learn his role as maoh and prove his worth, as well as trying cope with his easily-irritated new fiance.