Black Jack (TV) - episode 17 - 27 Feb, 2005

Rei is the school's star vocalist, until a polyp on her vocal cords causes her to lose her voice. Black Jack operates, but she can't remain silent for two weeks and reinjures her throat. Forced to be silent for three months, she becomes depressed, but befriends Sharaku's sister Wato, and eventually is able to regain her voice. (Source: Wikipedia)