Pump Up!

From ClubManga: Kayama Miharu enters her new middle school and immediately becomes friends with Mori Mizutama, a very cute guy she first takes to be a girl but is really a boy. However, though Miharu likes Mizutama, she cannot tell him, especially ever since the older Kawagoe (yes, a boy) seems to have taken Mizutama's interest instead. Miharu tries to be cute for Mizutama, but finds it practically impossible, as he is both more talented at home economics and more cute than herself. Then, Mizutama joins the Kawagoe's soccer club instead of the comedy-lovers' club the two of them had decided on earlier... Also contains the story Fuyu Hanabi