According to the terms of his late father's will, before Shougo Mikadono can claim his large inheritance he must attend a certain high school and find a nice girl there to marry. As all the girls he meets seem very friendly, Shougo only has to choose the right girl. But there's a slight problem: he has no idea which one of them is actually his younger long-lost half-sister. He can only hope he will meet and court his future bride without choosing the wrong girl!
Due to some mature themes/content, no one under 18 will be allowed into the anime room after 10:00 pm unless accompanied by a parent or adult legal guardian.