The Japanese are afraid of responsibility since what century exactly? I've never heard of that. I've only heard the opposite in fact: that being responsible is among the most important cultural things to the Japanese. You see it in the history of how they view employment between employers and workers for example. A general sense of making things right.
I think you'd be very hard pressed to find a people more responsible than the Japanese.
Probably has something to do with their high national debt. Many people seem to believe that high national debt reflects a population that chooses government subsidies over employment. You see that with Greece and Spain a lot.
Huh? Japan's employment rate remains extraordinarily high (3.6% unemployment, after ~20 years of recession!), and Japan's government debt is almost entirely to Japanese investors.
I think you'd be very hard pressed to find a people more responsible than the Japanese.