The answer to this question is completely obvious to people who spent formative years in Asia and are free of American/Western taboos (we have other taboos no doubt but not these).
Here is why there is no looting in Japan. Across the world -- in the US, UK, Canada, Brazil, South Africa and any country where they live side by side -- people of primarily Northeast Asian descent tend to commit crime at lower rates than people of primarily European descent, who in turn tend to commit crime at lower rates than people of primarily sub-Saharan African descent.
You can google the various crime stats if you aren't aware of this. Here are the California state statistics:
http://stats.doj.ca.gov/cjsc_stats/prof09/00/22.htm
Divide that by California population totals to get the rank ordering of violent crime rates by population.
You can also look at table 43 of the FBI Uniform Crime Reports, which is fine for establishing the black/Asian violent crime ratio, but which lumps Hispanics in with whites, inflating the apparent white violent crime rate.
http://www2.fbi.gov/ucr/cius2009/data/table_43.html
Similar stats can be obtained for other countries with a bit of googling. Now, the absolute magnitudes do change (1), which one could legitimately ascribe to the local culture. But the trend is very consistent.
There isn't a country across the world that I'm aware of in which people of primarily sub-Saharan African descent commit crime at a lower rate (or have higher educational levels, incomes, and so on) than people of Northeast Asian descent. Interested in counterexamples, but this appears to be a very consistent pattern.
Obviously there are other factors as well. But the probability of looting seems to be proportional to a group's propensity to disorganized violence (e.g. murder, rape, robbery) and inversely proportional to their ability to commit organized violence (e.g. military actions).
No doubt this post is extraordinarily blasphemous. But someone had to say what a good fraction of the rest of the world is thinking.
(1) Cultural variation seems to shift magnitudes but not rank ordering. That is, it does not appear to be a large enough factor to make Northeast Asian descent individuals in country X commit more crime than sub-Saharan African descent individuals in country Y. At least, I couldn't find any examples of this for any (X, Y) pair in the world, but perhaps you can.