At twelve, Tokushima Hikaru met Touma Kazusa at a music store. She was the exceptionally gifted and dazzling daughter of world-class pianist Touma Youko. The two spent half of a hot, restless summer together. But they never said goodbye. Hikaru was taken by her mother back to the hometown where her father lived.
Back in Chiba, Hikaru made a new friend named Kasumigaoka Utaha. She was shy yet bold, and brimming with youthful energy. Under the starry sky, the two made a promise: they would get into the same high school and keep exploring youthful romance light novels together. When high school finally began, Hikaru got her wish and attended the same school as Utaha, where she met many new friends.
On the last day of their second year, everyone gathered in the clubroom. Egged on by her friends, Hikaru sang a song to the sound of a piano drifting from somewhere around the school.
The clubroom door was flung open.
Touma Kazusa stood there, panting...
