Dear All!
I thank Barnett Pearce for reminding me of the relevance of research on shame versus guilt cultures for Japan.
See some of the references I found further down.
Most warmly!
Evelin

References:
Benedict, Ruth (1946). The Chrysanthemum and the Sword. Boston, MA: Houghton Mifflin Company.
Christopher, Robert C. (1983). The Japanese Mind: The Goliath Explained. Tokyo: Charles E Tuttle.

I found the following URL helpful:
Atherton James S. (2003) Doceo: Shame-Culture and Guilt-Culture [On-line] UK: Retrieved on August 4, 2004, from http://www.doceo.co.uk/background/shame_guilt.htm.