Shougo Mikadono’s deceased father left his son with a final request: attend his old high school to search for a suitable spouse, get married, and take his place as the rightful president of the prestigious Mikadono Corporation. Eagerly accepting the criteria, the teenager enrolls and quickly garners the attention of class rep beauty Konoe and one wealthy maiden after another due to his illustrious family legacy. What's more, Shougo then receives a very unexpected phone call from an unknown fellow student claiming to be his long lost sister - and she, too, wants to marry him! Can Shougo restrain his youthful desires while lustful beauties throw themselves at him in school, at home and even in his own bed long enough to determine who among them is his hidden little sister?
These two anime have very similar themes- romance/comedy, harem, and incest. As the male lead tries to avoid sibling love, he ends up meeting a bunch of girls who become romantically interested in him.