Three years ago, the former all-girl Himeno High School opened its doors to male students, but remains a female-dominated institution with the majority of students being girls.
One day Eikichi Mizushima transfers from prestigious Aoba High School in Tokyo where he was a member of the swimming team. While his father is away in New York starting a new business, Eikichi has decided to come to Himeji and live with his grandfather Kamekichi.
Yosuke Yamamoto had always wanted to establish a boy's sports club in school. When he learns that Eikichi belonged to a swimming club, he springs into action.
The other boys in the school include Senichi Kawasaki nicknamed "Wolf Boy Sen", the good-looking Iwao Iwata who is the only boy the girls talk to, and Hideki Sano, the rich son of the President of a major supermarket, who is always surrounded by fans. Eikichi's arrival soon influences the boys in school and changes their way of thinking.
Eikichi is surrounded by unique characters at the school. Shiori Yazawa, a senior at Himeno High, together with her parents Akira and Kaoru, live in a rented portion of Kamekichi's house. Kayo Oba, the student body president, is feared by the boys. Kozue Kitagawa, a devilish girl, belongs to the school wind ensemble together with Shiori. The substitute teacher Hijiri Saotome is a former swimmer at Tadano High School. English teacher Natsuko Ohara strongly opposes "men's synchronized swimming." Classic literature teacher Haruka Koshino hates men. And then there's the coffee shop owner Kozo Kasuya, who has something fishy about him.