In the months after the tsunami, there were actually MORE language teachers in Japan–and this trend continues. Using the MITI data originally popularized by Adamu at Mutant Frog, I’ve updated my five series graph from 2011:
Eikaiwa teachers actually hit a contemporary low around December 2010. (Ironically, the month I left Japan!) There was some bumpy numbers in early 2011, but—as you can see where the arrow is—higher numbers and steady revenue since March 2011.
A lot of urban legends around Tokyo. Were and are today, I would say. Let this not be one of them.
[Update: The major shakeup in the series, obviously, is when the old NOVA eikaiwa firm went bankrupt in 2007.]