This webpage is the singe best account I've read of a gaijin growing up in Japan. It's about a military brat who grew up around Tokyo in the '50s and '60s.

Here's a passage about speaking Japanese. Two words "manko-san"

http://www.geocities.com/Pentagon/Bunker/2260/speaking.html

Yours truly,
Roger
http://www.jingai.com/
Philadelphia