I know nothing of this show apart from
Actually that's not entirely true.
I know it was Golden Gash Bell in the original Japanese version. And that the US version involves digital underwear being worn by the title character.
The internet tells me it's about 100 demons battling on earth to find who will be the demon king. Sounds shonen tournament plot mixed with Pokemon to me. Is it?
EDIT: I watched a random subbed episode I found on Youtube. It reminded me a little of Shaman King, only better. The humour played out a better than that show did, and it doesn't suffer so much from being a clearly watered down Jojo's Bizarre Adventure. But there's definite similarities.
Oh and I see Gash is voiced by Ikue Ohtani (Pikachu, Tony Tony Chopper, Mitsuhiko Tsuburaya), who I've really liked ever since seeing her on the goofy Club Escaflowne extra on the second Vision of Escaflowne disc. Which outside of the Giant Robo extras is probably the best anime DVD extra I've seen. Jouji Nakata is awesome in it. But then he's kind of awesome by default.