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