The main character, Keiichi Manuma, is an ordinary office worker. He had a cute girlfriend with big breasts named Meiko Yurumi. One day, Keiichi gets an app called ``Eye Spy Sex Tuime'' that allows him to know about his girlfriend's sex information. Then, the app records sex information that Keiichi didn't know about. Is Meiko actually having sex with a man other than Keiichi? Of course I am! How will Meiko be fucked by the other man and how many times will he cum inside her? Please come and see for yourself.