I posted some time back about how the East Japan Earthquake is, quite rapidly, being forgotten. However, I think that when you spend some time to absorb the current culture of Japan (in my case, by listening to Japanese radio), it becomes apparent quite quickly that this isn't the case*.
Of course, without being in Japan, I feel that it is quite difficult to get an idea of how things have unfolded culturally, but even so, it seems telling that FM Hirakata is punctuated with references to the "Smile Again Project": a project where listeners compile messages to be broadcast every 11th by radio station(s) in the affected areas, with many of these messages also being broadcast sparsely through FM Hirakata's schedule.
In any case, while here in the UK the events of 11/03/2011 have been mostly forgotten**, it seems to have become quite a big piece of the Japanese cultural puzzle, which I guess is no less than anyone might have expected.
*In part, it shows that Google's statistics (like any statistics, I guess), should be used with a little more care before implying meaning. Supposedly I'm a scientist, of sorts; I really should know better.
**Leastways, I never hear people talk about it anymore.