Seeing this only makes me want Kura Oh to make an Oh My Goddess doujin. However I feel given how old this book is and how popular OMG doujin are that will never happen.
For the curious: Mara tricks Aoi by giving him supplements that turn him into a woman. Then Aoi does what seems to be par for the course when a man is turned into a woman, but wanting to get the full experience, s/he calls Nakajima. When Miyuki, Natsumi and Ken show up, Aoi jokingly tells them he made a deal with the devil to explain his female body. Then s/he asks to have sex with Ken because s/he's not sure how long s/he'll remain in that form.
Some funny things include Natsumi comparing Aoi to Marvelous Melmo (a magical girl that changed her age and body shape by eating certain candy), then proceeding to call Urd "Sadako".