When carmaker Mazda sneezes, everyone catches a cold, say people in its hometown of Hiroshima Prefecture, but these days, auto parts maker Yuji Yamaguchi fears a deep chill is on the way.

"If Mazda builds fewer cars, our orders will drop," said Yamaguchi, whose 110-year-old firm, Nanjo Auto Interior, has almost 1,000 employees making door panels and other parts for the automaker, which accounts for more than 90% of its sales.

"The key thing is whether we can remain profitable with lower volumes."