Japan's economy grew an annualised 2.2% in the final quarter of last year to rebound from recession triggered by last year's sales tax hike, according to government figures released on 16 February.
Growth, however, was weaker than expected as household and corporate spending disappointed, suggesting a fragile recovery as the sales tax hike hangover lingered and underlining the challenge premier Shinzo Abe faces in shaking off decades of stagnation.
Japan's top government spokesman said the government's decision last year to postpone the second sales tax hike plan was behind the recovery.
Nikkei share average rose to a near-eight-year high on Monday, helped by Wall Street's gains, while investors digested weaker-than-expected domestic growth data.
The Nikkei 225 average rose 0.8% to 18,031.84 points at midday, after reaching up to 18,074.26 earlier, the highest level since July 2007.
Japan's economy slid into recession during July-September last year, prompting Abe to delay a second sales tax hike initially scheduled in October 2015.
The slump slowed Japan's quest to beat nearly two decades of grinding deflation, and forced the Bank of Japan to expand monetary stimulus in October last year.