When you study for a test at a friend's house, it's usually hard to concentrate. And when a straight girl comes to a lesbian girl's room... she can't concentrate on studying! She touches her pussy in the kotatsu without anyone noticing, takes her to a corner of the kitchen to kiss and finger her... Rather than teaching her how to study, she is introduced to the pleasure of lesbian sex that she has never experienced before, so she will probably do poorly on the test...