The nation's once-thriving manufacturing sector saw its total workforce fall below 10 million for the first time in 51 years in December — down sharply from an October 1992 peak, when it employed just over 16 million, government data has shown.

With 9.98 million workers, manufacturers remain a major employer by type of industry, behind only wholesalers and retailers, which hired 10.35 million of the country's entire working population of 62.28 million.

But they are relocating factories from Japan — with its graying and declining population — to other parts of Asia in an effort to seek still-growing markets and lower operating costs. Elsewhere, some factories are shutting down, with operators being forced to pare jobs as part of restructuring efforts.