Anonymous Noise Vol. 1 (manga)

Nino Arisugawa, a girl who loves to sing, experiences her first heart-wrenching goodbye when her beloved childhood friend, Momo, moves away. And after Nino befriends Yuzu, a music composer, she experiences another sad parting! Both boys promised Nino that they would find her one day through her singing, so she holds on to that hope and continues to reach out with her voice. Now in high school, Nino serendipitously reunites with Yuzu, but she yearns to see Momo again