It's been just over three weeks since China increased checks on Japanese food imports over radiation concerns, but Kazuyuki Tanioka is already fearful for the future of his upscale Beijing sushi restaurant.

Like most restaurants in China, Tanioka's 8-year-old Toya has struggled with years of COVID-19 restrictions, which only began to ease late last year.

Now it is facing a shortage of both customers and seafood ahead of Japan's plans to empty into the sea treated radioactive water from its disaster-stricken Fukushima No, 1 nuclear plant.