Immoral Sisters 3: Blossoming / Ai Shimai Tsubomi... Kegashite Kudasai

The plot of the anime "Yamazaki Sisters" centers on Kikuhime and Sora, high school girls who do everything together and share a crush on the same guy. However, this guy, as it turns out, is not as simple as he seemed. He not only flirts with his sister, but also pays attention to his teacher Mastubara, who has an attractive figure.