This is Mabataki Made

In the winter of her second year of high school, Fuko was asked by her art club classmate Alan to pose for him. She did so in the classroom early one morning, but for some apparent reason she experienced a climax and fainted. The homeroom teacher who happened upon the scene misread the situation which resulted in Alan’s expulsion, thus estranging the two. Eight years later, Fuko cannot by any means forget the orgasmic sensation of that day. She pays Alan a visit and compels him to once again draw a picture with her as the model.