firstly, the random website my one batch of scans from had Track 17 done, in which Ryuichi demands (while wearing a Kumagoro suit, mind you) that Tatsua take him to see the capybaras. Then there are little manga capybaras on the next page
*dies of squee*
Then, i stumbled across a forum with links to all the Gravi Remix doujinshi, mostly scanlated.
Gravi Remixes are fabulous, because it's the same artist who does the regular manga, doing her own doujinshi. Explicit Shuichi/Yuki with Hiro and Sakano watching? ee hee hee hee!
I just don't think it gets any better than this (this being a thoroughly post-coital Hiro).