虜姫 ～白濁まみれの令嬢～

Young master Tsuruma, son of the owner of Tsuruma Consulting, has access to an institution full of inmates used for testing. He abducts female classmates from his school and has his way with them, letting the inmates rape them too. They endure multiple rapes as they try to find a way to escape with the help of a female guard.

[From ANN]