Kiyohiko Azuma is the creator of both Azumanga Daioh and Yotsuba&!. He also put together two anthologies, which included a couple other works, like Try! Try! Try! and Wallaby.
He also did some hentai. But we won't talk about that here. ;D
So, I have a question: has anyone seen proof that the "Azumanga Ohdama" exists? It's supposedly an Azumanga Daioh sidestory featuring Mr. Kimura, but I haven't seen a shred of proof that it's real, beyond a brief wikipedia mention.