Houkago no Ane ~Hakudaku Rinkan Ryoujoku no Wana ni Ochita Amemiya Mana

Mana Amamiya, the most beautiful girl in the entire school.
Her beauty is the envy of all her female classmates, and her large breasts are enough to excite all the boys with a single look!
However, her beauty and her large breasts were every day under constant assault from the teacher "Tatsuya Katsuragi".
It all started when her little brother "Jun" became a bullying target.
She consulted with Katsuragi on how to get her classmates to stop bullying her brother...
...but in order to help her, he wanted her body!

[From DLsite English]