The jobless rate hit a trough of 3.6 percent in July last year, which was the lowest since February 1998.
But it has since crept back up as companies have become more cautious about the business outlook amid a slowing US economy and high oil prices.
The jobless rate registered to 4.0 percent in September and October before
dropping to 3.8 percent in November and staying flat for three months.
Japanese corporate profits are being squeezed by record oil prices, higher raw-materials costs and the yen's 13 percent gain against the dollar this year.
Also on Friday new figures showed Japanese inflation rising to a 10-year high, with the core consumer price index, which excludes volatile fresh food prices, rising 1 per cent in February, the fifth straight month of gains.
"Companies can't afford to hire employees and raise wages even if they want to," Takehiro Sato, chief economist at Morgan Stanley in Tokyo, told Bloomberg News.
Unemployed Japanese queue to find work at a
Tokyo job placement office [GALLO/GETTY]
"Profits are under pressure from oil, the surging yen, the US slowdown and more reasons I can't even count."
On Friday in early morning business the yen traded at 99.54 to the US dollar, up from 99.44 before the latest figures were released.
Japan's government lowered its assessment of the economy for the second month in March, saying the nation's longest post-war expansion is "pausing" and consumer spending is "almost flat."
"The virtuous cycle of corporate profits feeding into wages and spending has begun to collapse," said Junko Nishioka, senior economist at ABN Amro Securities in Tokyo.