You are Takuya Aihara, the hero/heroine of the story. You've been blessed with a very interesting life: a few years ago, due to a freak chemical accident, you were turned into a girl, not once, but twice. Now that you're approaching your final year of university with your loyal friend Asuka, you almost feel nostalgic remembering those crazy days you spent as a child.
Until it happens again, that is: that annoying Koji, still madly in love with your feminine form, secretly forces Asami-senpai to prepare a gender reassignment potion and tricks you into drinking it! This time it will be harder than ever for you to become a man again, but you have no choice: you need to find a way to return to normal before your female body becomes permanent.
Even though Asuka is one of the most understanding women in the world, there is no way she will stay with you as a girl - it's just not her thing. As you begin another round of bizarre sexual adventures in your female body, virtually all the characters from past X-Change games return: your perverted sister Natsumi, who loves to tease you; the brilliant Asami-senpai; the endlessly experimenting Chisato; and many others from the first two games.
With an even richer and more complex plot than last time, you'll have a lot of fun exploring college life in your new female body and discover many interesting storylines. Where will it all end?