Yuri Love Slave: Futari Dake no Houkago

Overview

Asakura is an ordinary high school girl. One day, she sees Reina, the cold and stuck-up class president, going into a bookstore. Asakura follows her in and discovers that the book Reina bought is a gay manga. Feeling shocked and slightly ashamed, Asakura opens the book, and as she reads, she starts feeling funny inside. The little devil in her head whispers to her, "Asakura-chan, do you want to try the things in this book? Do you feel turned on?" Ignoring the angel's warning on her right shoulder, Asakura's gives in to the devil's seduction, and her gay adventure with Reina begins...

Source: AniList