Sayorin

In Memories Off ~Sorekara~:
A second-year high school student who belongs to the Naginata club. She is an underclassman of Isshu that is in love with Shin and admires Miyabi and calls her "mentor". She introduces herself as Sayorin because she doesn't like her last name. Although she does not reveal her real name in the game, it is strongly hinted what her last name is. For example, she's aiming to be the "woman amongst women".

Spoiler

She's Rikimaru Shinkurou's younger sister.

Also, she's a capturable character, thus she has her own route.

In Memories Off ~Sorekara again~:
A third-year high school student.