Shokushu Library 2
As you look around, pretending to study the books, your gaze is drawn to a boy and girl sitting at a table. The girl looks quite pretty in a studious sort of way while the boy could be anything, as his face is obscured by a book he seems to be reading. They appear to be seated rather awkwardly and after a few moments of surreptitious study, you realise why. The girl's short skirt is pushed up, exposing the full length of her slender legs, which are slightly parted. And that is surely not her own hand wandering over the white cotton of her panties. The boy is touching her up under cover of the table! That movement must have been what attracted your attention.
After a while, the girl puts down her spectacles, gets up and disappears to a more secluded part of the library. A couple of minutes later, after looking around carefully, the boy follows her. Something seems wrong here but it takes you a while to figure it out. Then it hits you. This is an all-girl school, so what is a boy doing here?