"If my guy friend turned into a girl, he would be the perfect girlfriend!" Returning to his hometown after 10 years, Amano Koichi is thrilled to finally reunite with his childhood friend, Yukio Sawatari on the first day of school when suddenly, he turns female! Yukio is affected by "Sudden sex change syndrome", a rare condition present in one every ten thousand people which randomly changes their gender!Koichi can't help but be flustered by his childhood friend's cuteness. How will this complicate their relationship? Will it develop into a forbidden romance?! Find out in this exciting TSF Rom-com!