Japanese business folk in China are not short of grumbles these days, what with the unpredictable officialdom, congested roads, soaring prices and thickening smog.

Yet such irritations are clearly not deal-breakers. After holding relatively steady for years, Japanese foreign direct investment in China jumped nearly 50 per cent in 2011 to $6.3bn, according to data from China’s commerce ministry. The Chinese numbers are far from perfect – much foreign investment gets funnelled through Hong Kong, for example. But Japanese statistics show even bigger expansion in investment last year. Something is clearly afoot.

Dai Hakozaki of the Japan External Trade Organisation’s Beijing office suggests that some Japanese companies finally took the plunge on projects long under consideration. The anaemic growth of Japan’s domestic market has certainly focused corporate attention overseas. The dramatic rise of the yen is forcing even hidebound exporters to consider moving offshore. The currency’s strength also makes overseas investment look cheap.