Hachishaku Hachiwa Keraku Meguri - Igyou Kaikitan Doujin

Some of you might know the book by Jyoka about a guy who participates with his female taxi driver in a funny game of telling (hentai) horror stories. Well, there seems to to be a (amazon exclusive) sequel(?) doujin and I wanted to know if someone got it and could tell me what happens in the story. I couldn't find it on the net so maybe someone here can help...