From Shoujo Crusade:

"I wanted to create a summery, sparkling youth." - And so the theme is "yosakoi*"!!

For the sake of medical treatment for her younger sister, Natsume ending up moving from her home to Shikoku. In a place where no one knows her, she'll make her high school debut as a "cool beauty"! ...This determined Natsume is approached by the wild child-like Yudai saying, "enter my team"??

Eeh!!? What do you mean by team!!?

*For more info on Yosakoi go here.