While shuffling his family aboard the 16-deck Quantum of the Seas in Shanghai, Yu Zhihong admitted he has often told his kids that Japan is no good.

That did not stop the 45-year-old salesman from booking a trip across the East China Sea to his country's longtime rival. "Japanese people are nice and have some good qualities," Yu said ahead of his cruise last month. "I'm only upset with the Japanese government because we need to respect the history between us."

Four million of Yu's compatriots are expected to head to Japan this year to eat sushi and snap up rice cookers and electronic toilet seats, a two-thirds increase from last year. More than 40 percent were from the greater Shanghai area last year, according to the local Japanese consulate, while Beijing accounted for about a quarter of Japanese visas granted.