My Friend's Little Sister Has It In for Me!

Kousaka Kyousuke, a normal 17-year-old high school student living in Chiba, has not gotten along with his younger sister Kirino in years. For longer than he can remember, Kirino has ignored his comings and goings and looked at him with spurning eyes. It seemed as if the relationship between Kyousuke and his sister, now fourteen, would continue this way forever. One day however, Kyousuke finds a DVD case of a magical girl anime which had fallen in his house's entrance way.

Is insanity hereditary? Shougo Mikadono's beginning to think so, because the terms of his late father's will seem crazy and following them may drive Shougo bonkers as well. Oh, it sounds simple at first: before Shougo can claim his VERY large inheritance, he just has to start attending a certain new school and find a nice girl to marry. It's a little unromantic, but perfectly do-able, right? After all, all the girls seem quite friendly, so all Shougo has to do is find one he has something in common with. EXCEPT, and here's the kicker, it turns out that Shougo has WAY too much in common with one of them, because she's actually his long lost sister! And he has no idea which one she is! Will Shougo meet and court his Miss Right without committing something very morally wrong? Can he find his future bride without slipping into the wrong set of genes? And if his little sister does reveal herself, just how much will be revealed and under what circumstances?

Mahiro Oyama was just a normal erotic-game loving dude…until he woke up one morning as a woman! Turns out his mad-scientist little sister, Mihari, tried out one of her new experiments on him…with a disastrous outcome, as far as Mahiro’s concerned! But Mihari is as determined to study him as he is determined to go back to his shut-in, game-playing life, and one thing’s for sure…life is going to get a whole lot weirder from here on out!

She smiles just for me. Her name is Kachi Shirokusa and she's even an award-winning high school girl writer! And she's beautiful! I know that she's totally out of reach for me, a normal high school kid named Maru Sueharu! But I think something's there... No, there's definitely something there! Or so I thought... but Kachi has a boyfriend?! Seeing me depressed, my friend ever since we were little who's cute, cheerful, and loves to look after others, Shida Kuroha... who also apparently had no problem telling me that she likes me for some reason just suggested, "Let's get revenge."