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 usually are not associated to him by blood – the gorgeous Ako and Riko, who’ve emotions for him which might be removed from sisterly and present it each probability they get, whether or not it is to pry into his mattress or convey him lunch at recess. After which there are classmates, and pouring oil on the hearth. And what’s the poor man to do?