It's really a shame they never finished what they started in terms of anime.
I'm currently reading the manga at 11 of 15 volumes and it's a really great manga. The anime could have been equally good, although they did already step up the pase quite a lot so they wouldn't need too many episodes, but evenso, it seems it never caught on.
A shame really.
So, if you have watched this already, then rest asured, you can read the manga for the full story, start to finish.
If you haven't seen this yet, I'd still recommend the manga over the anime, but it is funny to finally get an audio with Kitano-kuns undescribable screams. =P