The US dollar last year was 117 yen.
That means a $399 PS3 would yield Sony 46683 yen.
Today the US dollar gets 94 yen.
That means a $399 PS3 will yield 37506 yen.
So today, a PS3 gets 9177 yen or $97 less than a year ago simply from currency rate changes. Bottom line is they receive 25% less yen than a year ago selling at the same price in US dollars.