I'm not sure what you are looking for, but here is my 2 yen worth. The Japanese don't generally carry their wooden buki around in my experience. Mostly they keep them in the dojo. When they do carry them, it's generally in what you would probably call a "western" style bag, though I assure, the ones on my site at http://budogu.com/shopsite_sc/store/html/page12.html
are all made in Japan, and they are what the Japanese use. I don't think I've ever seen a handmade carrying case in Japan, though I have seen some beautiful bags for storing shinken in, these aren't for carrying though. For really nice handmade stuff, I'd recommend going to Janet Rosen at Zanshin Art. Her site is HTTP://WWW.ZANSHINART.COM
and her email is JANET@ZANSHINART.COM
She makes some wonderful cloth bags for carrying weapons and equipment.
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