Giniro no Refrain

Overview

Sharon is a young girl who aspires to be a pianist, and Silas is a boy who is a prodigy at the piano. The two become close and are attracted to each other through their music, but they are unable to be honest with their feelings due to trivial matters... Also includes the side story Kashinoki Monogatari, about a boy obsessed with an oak tree that is said to make wishes come true. (Source: Kodansha, translated)

Source: AniList