why should he be paired with only one. to love ru got canned and had a true harem end. but she also made a damn good point, he would be the ruler of the universe and to hell with earths laws, you rule the universe, you make the law, lets all be together. now this whole manga is based on a "taboo" if you call step siblings a taboo, so why not break some more. i mean in the bit i have read of it, the two sisters seam to be a hell of alot close than sisters should be, and almost all the conflict starts with them not wanting him to be with he other instead of her. in all honest i think that him deciding that that law is retarded would be the best ending for this manga. again im not to far into it so i may be wrong.

By chapter 8 or so(don't remember which exactly) Keita has a flashback of when he was young and how he wanted to marry both his sisters. His father replies by saying that it's illegal, which saddens the young Keita. In later chapters, he openly admits that he loves them both, which makes it clear that Keita will have to make a decision one day: Who will he choose? The sweet, closet-pervert Ako? Or the tough, honest Riko?

It's because of the decision, and how they both are given the same amount of focus, that I really hope it doesn't have a Harem/improper ending. to-LOVE-ru, a series I fell in love with, had the same problem with the ending. Keita needs to choose one of his two sisters, and we, the readers, should get a foreshadowing when the manga nears its end, about who Keita will choose. His sisters love him too much, and he loves them too much, for Keita to not pick any.