Sweet, Shameful Guinea Pig -Sadistic Doctor's Secret Laboratory-

After losing her job, Natsumi comes home to find that her boyfriend has disappeared, leaving her with a debt of 3 million yen... To pay off the debt, she takes a job that offers the unbelievable salary of 3 million yen for one month. However, it turns out that her job is the test subject for a new drug... an aphrodisiac! The drug turns her into a horny beast, and she is repeatedly violated by a sadistic man...!