From: 	Caroline Ann Seawright[SMTP:kunoichi@yoyo.cc.monash.edu.au]

Say, where did the Naban mirror first appear anyway? In the manga, anime or 
fanfic? I'm pretty sure I never saw it in the manga before.

It's not in any of the manga that I have, (that I could see!) and I've got 
them all, apart from #37 which isn't out yet... ^^;;;

And I've seen every volume since Happosai's appearance, and I'm sure I would have remembered something as powerful as the Naban mirror. And since it allegedly came with Happi, it could not have appeared earlier, right?
That leaves the anime (TV AND OVA) or the fanfics, so which is it?