Across Japan, foreign workers are keeping factories, fisheries and workshops afloat. But as wages rise in neighbouring countries, many business owners worry that Japan may no longer be an attractive destination for this workforce.In Choshi, home to a large fishing port in Chiba prefecture, east of Tokyo, one long-established cannery offers a glimpse into both Japan’s dependence on foreign workers and efforts being made to retain them.Ho Thi Thuy Nhung, 38, begins work at 8am on the assembly...