Core consumer prices rose in December from a year earlier, government data showed on Friday, climbing from the previous month, but inflation was still well short of the Bank of Japan's elusive 2 percent target.
The lackluster data, which was also boosted by a sales tax increase last October, underscored the challenge faced by the central bank, which was expected to maintain its current stimulus policy, analysts said.
The core consumer price index, which includes oil costs but excludes volatile fresh food prices, rose 0.7 percent in December from a year earlier, the data showed, matching a media forecast. In November, the index rose 0.5 percent.