Kayama Ayumi is a pharmaceutical engineer who has developed many new drugs. Even though Ayumi is commended by the public, she doesn't experiment with drugs for the sake of the others, but only to satisfy her own curiosities.

One day, Ayumi set her sights on the protagonist, who came to work part-time as a clinical trial. Offering the protagonist, who is a self-supporting student, the amount of money more than what he would have earn form his part-time, he immediately agreed to become her specimen.

With her hands on a high-quality​ specimen, Ayumi's curiosities begin to overflow.