Japanese game industry trade body CESA (Computer Entertainment Supplier's Association) recently polled nearly 2,000 game devs in Japan about how much they're paid, and the results suggest it's less than devs in the West.
Some of the numbers seem remarkably low. According to Kotaku's translation, the average salary of a producer in Japan was roughly $76,600, but the average salary of a Japanese game artist was ~$44,400.
Compare that to Gamasutra's most recent salary survey, conducted in 2014, which suggested that the average salary of a producer in the U.S. was $82,286 and the average salary of a game artist or animator was $74,349.
This is notable discrepancy, though it's not novel; back in 2010 we reported (based on results from two different surveys) that the average dev salary in Japan was 27 percent less than the average American game dev salary. As far back as 2007, developers who worked in Japan were reporting that "the salaries paid to game developers are low compared to the West, especially the US."