Or, at least, that's what they are according to TokyoPop, the one issue I ever bought. I asked a Japanese foreign exchange student about them, and he had no idea what I was talking about. Nnn.
Anyway, their music is exceedingly nifty, by my standards. Bouncy. Uplifting. Funny, at times. I'd include more information here, but all of the websites I can find about them are in Japanese. ^_^. I can, however, suggest a few titles.
Their music is necessarily very expensive, as it's imported from Japan where CDs are around $20 a pop. Everyone loves them on Napster, though, so you shouldn't have much trouble finding some of their work.