Intron Depot 3 reprinted the vast majority of these images, with a nod or two from Intron Depot 2 as well. As I haven't really come across the images anywhere else, most of these were likely used as Comic GUM magazine covers initially. Nothing wrong with that of course, it just makes me want to get a subscription to the magazine so I can get these things on their first go around, rather than when they get collected. As to my favorites for the calendar, May and August are readily my top picks, and March would have been a shoe-in if it weren't for the overly orange getup, but as it stands, September makes the cut as my 3rd favorite this go around.
So far as I can tell, the entirety of this calendar is entirely work for Comic GUM and other private commissions. With so many images that I like in this calendar, it's hard to choose just three to let you guys take a better look at. I think though, that I'm going to have to say June, July, and August are my favorites though, and made for a pleasant summer of calendar imagery. This was a fantastic calendar, and one every Shirow fan should strive to find for their collections. Alternatively, you could take the easier path and go get Intron Depots 2 and 3, which contain all of it between them.
This calendar seems to be more of a collection of art pieces Shirow has done for various, smaller projects that people have actually heard of like Jaishin Hunter and Sampaguita, along with a few more GUM covers. This time around, my favorite pieces are April and August. March is worthy of mention as well, just for focusing on a guy instead of one of Shirow's normal beauties. About half of the imagery in this calendar also appears in various places within Intron Depot 3, albeit rearranged a bit sometimes, as well as a couple of them showing up in Intron Depot 4(which I unfortunately don't have yet).
Thrilling was a slick looking calendar, serving as a nice little showcase of Shirow's current CG skills. Unfortunately they decided to throw a big border around all the images this time around, rather than letting the images go all the way to edges as usual. A couple of the pieces here first showed up in the Uppers Posterbooks, but outside of that your best bet is picking up Intron Depot 3, which has everything found here, and definitely helps makes it worth the purchase. This calendar has so many good pieces to choose from, but July, November, and December stand out as my favorites.
Now this is an interesting calendar, and so far as I can tell, the only thing is has any relation to are a couple images out of the Posterbooks. What makes this one particularly interesting though is the pair of side projects associated with this calendar. First is Togihime, which gives us a collection of nicely sized posters featuring each of the images in the calendar, plus an additional poster if you managed to get the limited edition. The other related item is a pair of CD cases, featuring two versions of the calendar art. Those in the first case match the images here, while the second case contains an alternate more erotic version of each of the images. While I can't show you the erotic ones here, I liked April, June, and October's images the best in both versions.