Maihime Terepsikola(2000)

The story focuses on classical dance and its meaning for the three teenage protagonists: Yuki, who is ending the first primary; Chika, her older sister by one year; and the strange Kumi, whose family has fallen into disgrace by the debts of her father (because of which Kumi is also forced by her mother to pose for pictures). The aunt of Kumi, Michiko, was once a prima ballerina, and perhaps, the girl has inherited her talent…

(Source: shoujo-manga.net)

Note: Won the 11th Tezuka Osamu Cultural Prize in 2007.