From the back cover of the 2004-2005 MK Catalog:

www.CINCA.JP [email protected]

Kato Model Aircraft Co., LTD.
No 8-1, Esaka-Cho, 2-Chome
Suita, Osaka
564-0063
Japan

I haven't tried their 'website' in 2 years or so. The last time I was there it only had a home page with no information.

Contacting Singapore hobbies is a pretty good alternative. Searching the web for a Japanese hobby shop that sells internationally might help.
Good Luck,
Will B.