The Dancing Princess Terpsichore - Maihime Part 1

(from ebookjapan):

Rokka Shinohara is in the fifth grade of elementary school. She has been learning ballet with her older sister Senka under the supervision of her mother, who runs a ballet school. One day, a mysterious transfer student came to Rokka's class. The new student also seemed to be learning ballet...

The fates of those who are fascinated by ballet now begin to gently intersect and turn. Ryoko Yamagishi's masterpiece full-length ballet manga, Volume 1!