Nononono(2007)

Nononono

Nonomiya Yuuta, a Skii Jumper aiming for Olympic Gold, bursts onto stage with his exceptional skills. However, his biggest problem is that he is not really a "HE"... This Yuuta is actually Nonomiya Yuuta's twin sister, Nonomiya Nono... And with Women's Skii Jump not being an Olympic catagory, hiding her true identity is the only way for her to achieve the dreams of her father and brother.

(Source: MangaHelpers)