Pretty awesome comic by a japanese artist on Okashi blog.
http://okashi.blog6.fc2.com/blog-entry-11855.html
From my very low level of Japanese language, I can make out some of the Katagana. "Succubus" is in the first panel. So my guess is they were looking for a succubus shrine to get some action, misinterpreted it, and got TGed. Part of the last panel is "I messed up..." "So that's what it meant...."
In the second comic, after they're women, I assume he found a solution. The third panel says "Incubus", so they go to an incubus shrine - except this one doesn't change them and actually has incubuses that have fun with them instead.
I don't know Japanese very well, so it'd be nice if someone could provide a translation of the panels - still a funny comic if you don't understand it.