Nanami is ridiculed by her friends as 'Nanami-chan' because she looks feminine. I decided to confirm one of the seven mysteries that was passed down to the school through a courageous test. Rumors of' Hanako-san' in the toilet on the 3rd floor of the old school building. Nanami went to the bathroom to confirm the true meaning of the rumor ... There, Nanami's body, wrapped in a mysterious light, turned into a woman.