Before he one morning awoke as a woman, Mahiro Oyama was just a regular guy who enjoyed playing erotica games. It seems that his crazy-scientist younger sister, Mihari, conducted one of her brand-new experiments on him, and the results were devastating in Mahiro's opinion! A lot crazier things are likely to happen in the future since Mihari is just as keen to study him as he is to return to his reclusive, game-playing existence.