Oh wait, he is. My fault, got confused there. ^^'
I actually thought Carmina was a girl. Oops! ^^;
Unless I'm mistaken, most of the art on his tumblr
is his. If so, he's pretty good!
That aside, Ariga's art is just plain awesome. Where did you find that anniversary pic? Did he post it to his deviantart? He doesn't have a pixiv account, does he?