Boycotts of Japanese goods in the wake of a diplomatic row with China sent the nation's exports plunging last month, according to official figures.
The dispute over the sovereignty of the Diaoyu islands in the East China sea has seen Japanese car makers report tumbling sales to China in September, with Toyota's sales slipping by nearly half.
Overall exports to China, which overtook the United States as Japan's top market in 2009, fell 14.1 per cent year on year in September, the biggest decline since January.
The nation's exports to the rest of the world were down 10.3 per cent in the year to September, the biggest decline since the aftermath of last year's earthquake and tsunami, adding to fears that the country might slip back into recession. Confidence among its manufacturers is at its lowest level for more than two years as the eurozone's debt woes also hit trade, potentially triggering more stimulus from the Bank of Japan.
The BoJ has cut its economic assessment for eight out of nine regions in Japan because of slowing growth overseas.