John R. Yamamoto-Wilson wrote:

> http://www.ling.ed.ac.uk/linguist/issues/12/12-1871.html

Actually, that's not terribly helpful! Here's another link, with people 
arguing whether, if fact, it's the other way around, and the Portuguese 
word actually derived from the Japanese one:

http://tinyurl.com/zcldy

Anyway, I have to eat my words; here's a Wikipedia article (in 
Portuguese) debunking the notion that the words are in any way related:

http://pt.wikipedia.org/wiki/Palavras_japonesas_de_origem_portuguesa

Egg on my face again!

John
http://rarebooksinjapan.com