When Aiko was still young.　1 (Pixiv Fanbox)

When Mika's classmate Aiko, who also shared a dorm room with her, was still very young. Her try to learn from Aiko's brother, but... -------------------------------------------------------- Aiko: Shin, do you really know sex? Shin: I learned it from my mom, but you're not ready yet, Aiko. Two more years. Aiko: I can't wait to be taught a lesson!