Well, that was super cute...and the sex was pretty well-drawn, too. Also, I laughed out loud at the author's note; by all means, I think it's great when an author sticks with one pairing, as long as they like.
Finally a doujin where Reimu doesn't mind stopping being a weak human. Wonder what sort of youkai it would be possible for her to become. Becoming a vampire will probably be the easiest