Nagase Jun'ichi♂

Jun'ichi 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 fiancée as arranged by his family. He had a reputation of a delinquent in junior high school until his sister Minato decided to move in with him. He has a snarky attitude and is often teased by everyone around him, including his teacher. 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.

[From Wikipedia.]