Anti-Japan riots in Beijing, Shanghai and elsewhere in China in September triggered by Japan's nationalization of the disputed Senkaku Islands brought vandalism and violence to Japanese restaurants, stores and car dealers and a boycott of Japanese products.

The disturbances prompted Japanese companies to worry that they have been too dependent on China for their sales and production and thus should consider diversifying their global exposure.

The "China-plus-one" concept, in which firms look to establish footholds elsewhere in Asia, was fostered several years ago but since September has gained greater traction.