Futami Seiji

Penis Length: 18 cm

The protagonist himself. Seiji used to attend the all-boys' school next door, but was then forced to cross-dress as his twin sister by his own twin sister and attend her school as her. They both share the same face, but their personalities are completely different. Unlike Sena, who is smart and very confident, Seiji lacks confidence and is a tad timid. He is neither good at sports, studying or socializing; it's as if his twin sister sucked out all of his good traits to herself. So it comes out as quite a shock to him when he finds the whole school worshipping him.

His dick in its normal state is pretty small, however, whenever he pops a boner over anything it turns out to be 18 cm (~7.1 inches) long. After losing his innocence to Chiharu, the other girls in the academy start lusting after him, becoming even more intrigued of his holy weapon resting inside his pants.