Shiori Hasegawa

Shiori Hasegawa (長谷川 詩織 Hasegawa Shiori) was Hisako Kajiura's kōhai at Seio Girls' Academy during Hisako's school days who was good at the piano that she was a scholarship student of the music class at the school.

Trivia

 * Shiori does not appear in the anime version.