Junichi is the main protagonist of the series. He is a second year high school student and had a quarrel with a transfer student, Yuuhi Katagiri on the first day of school. It turns out that Yuuhi is his fiancé as arranged by his family. His life takes a drastic turn with Yuuhi entering his life.When he first met her he had the impression she was a helpless girl and kissed her because of a misunderstanding. After that, Yuuhi becomes much more violent towards Jun'ichi. Since Yuuhi is often harassed, he finds himself protecting her; as time progresses, their love for each other grows, even though neither of them will admit it. Throughout the anime series it is hinted that Jun'ichi has romantic feelings for his sister Minato, but he is reluctant to admit this even though he sometimes has fantasies about her.

Spoiler

However, in the final episode, he realizes that he cannot live without Minato and confesses to her, for some sweet (or so they think) incest action!