Rumi Natsumi is the fearless leader of Telephone Communication Madonna, a phone sex line that occasionally sends girls to meet a select few of their lucky customers in person. As the owner, Rumi handles all of their most difficult cases—so when a call comes in from a young man who completely loses control when aroused, Rumi knows that she herself is the right girl for the job. However, when she meets her client, Ryo Sugiura, the case turns out to be much more complicated than she expected. He does not just lose control—he transforms into a giant monster!