Dai Ni Gakusho

Shirase Mari and Endo Natsumi are violinists in the same orchestra. They both work hard, but Natsumi becomes pregnant and quits playing the violin. She soon marries the cellist in the orchestra. Meanwhile, Mari is chosen to become a solo violinist and becomes popular. 17 years later, Mari and Natsumi meet again by chance. Mari finds her being envious of Natsumi's life, while Natsumi finds herself feeling the same about Mari's life.
(Source: DramaWiki)