尾上 沙希

She is an active schoolgirl attending an elite school in Tokyo. She is a childhood friend of Shizuka's and has protected her from boys and bullies. She and Shizuka are in the same class

She is the chairperson of the class committee and a karate expert, and has a very competitive side. On the other hand, she is surprisingly interested in girls and hates men because of it.

She has an eye for all things cute, and has been attracted to the cuteness of Shizuka without her glasses since she was a child. She masturbates every night, indulging in lesbian fantasies.

Even so, she continues to adopt the attitude that she has no interest in such things. She is suspicious of Akihiko's approach to Shizuka, and interferes to get rid of him. However, she ends up getting involved with Shizuka and is forced to participate in Shizuka's sex experiments.