Keita is a Japanese schoolboy in his third yr of highschool who’s getting ready to take his highschool exams. He has two half-sisters who will not be associated to him by blood – the attractive Ako and Riko, who’ve emotions for him which can be removed from sisterly and present it each probability they get, whether or not it is to pry into his mattress or deliver him lunch at recess. After which there are classmates, and pouring oil on the fireplace. And what’s the poor man to do?