Finding Japanese catalogues is not easy - fortunately several makers still offer a wide range of blade shapes for both 'nata' and 'kama'. Unfortunately they are in Japanese, so pictures will have to suffice...
Pages 10 to 18 show the kama they make
Pages 20 to 25 show the nata they make
Page 28 shows the socket nata for fitting with an axe type of handle
Tosahamono (Japan) Catalogue.pdf
Adobe Acrobat document [7.4 MB]
The web site of Tosahamono can be found at http://tosahamono.com/