Kazuma is a 22 years old, ordinary University student. He's currently working at the dormitory of all-girls school's basketball club as a "slave". Cleaning, preparing meal for the members, and many things. In 4 April,when washing clothes, he found a girl's underwear, yep that's Sae's. He is forced to become her sextoy... but someone is watching them silently... Will he succumb to the lolis and become their slave forever?