Many Japanese companies are now struggling with major staff shortages because Chinese workers fled the country after the earthquake and tsunami hit a few weeks ago. Restaurant manager Yu Yoshida is managing with seven workers after 15 left for China, and he is now wrapping dumplings himself. "I'm in trouble," he says. "We can cope with the existing staff, but if [more] customers come back, I'll be in trouble." Indeed, the welcome sign of customers returning to stores and restaurants is bittersweet for many business owners after tens of thousands of Chinese students and workers left the country in mass evacuations. It reveals the long-running problem in Japan of an aging population and a shrinking domestic workforce that could prevent a full recovery. Some immigration experts say the disaster has made the need for revision to the country's closed immigration policy even more urgent. "In order to recover, we have to rely on foreign workers" says Hidenori Sakanaka, executive director of the Japan Immigration Policy Institute.