I thought the two might be related too at first, but then I checked this close up picture I have
http://picasaweb.google.com/assis.micha ... 5302719970
Zooming in, you'll notice that in Naoki Takeda's guitarist, half the guitar comes out of one arm, and the other half out of the other arm. In the guitarist in question, the guitar comes from the torso/upper leg area.
Notice also that Naoki's guitarist has a collar, while the other one doesn't.
It's possible they're from the same creator, of course, but the designs are structurally very different, so it's impossible to say.