Keita is living many junior high school boys' dream. He has two older step twin sisters who compete for his romantic love in so many ecchi ways: good morning kisses and panty flashing. Their parents openly support the sisters' feelings and advances because they are step-siblings and are not related by blood, in fact they even have a bet going as to which sister Keita will accept. Now, if only the sisters were not so popular, because they have asked their little brother to attend their high school where there are certain to be problems.Based on the same-name manga series authored by Ditama, whose other manga titles include Mahoromatic and Kibun Kibun.