Eighty Eight Divided by Two

Mitsuru Fujita is a girl who loves playing piano. When she moves into her high school dormitory, her roommate is Kanade Kobayashi, a former rival at piano competitions. She was hailed as a prodigy, but Kanade has given up the piano due to trauma she suffered while studying abroad. Until Mitsuru invites Kanade to play a duet with her...

Source: Manga Time Kirara, translated