Well I don't have any NJS certified items but it would be hard to get all the lines in the kanji characters for Nihon Jitensha Shinkokai in a 1cm high stamping. And like how Fugazi Dave posted, Nihon Jitensha Shinkokai is 8 characters long. I can read a bit of Japanese, and at least the first 5 characters are correct.

I should have been clearer with my post, and my percentage was just a shot in the water. I was meaning for the most part, a lot of english is used for consumer items and a lot of shop signs. Coca-Cola is done in english, the major beer companies, Sapporro, Asahi, write out their names in english, Sony, Canon, Nikon, Panasonic, label their products in English.