The world's third-largest economy surprised markets on Wednesday by reporting its fastest pace of annualized quarterly growth in a year.
Real gross domestic product (GDP) for the January-March period expanded an annualized 1.7 percent against expectations in a Reuters poll for a 0.2 percent rise. On a quarterly basis, GDP grew 0.4 percent against a poll forecast of a 0.1 percent quarterly gain.
Eisuke Sakakibara, Japan's former vice finance minister, now a professor at Aoyama Gakuin University, said the first-quarter report card confirmed his bullish view.
"I was expecting a strong read because the economy is in recovery," he told CNBC's "Squawk Box." This year, it's quite likely growth will be around 1 percent so the recovery is going on fairly smoothly."
Wednesday's report marked a significant recovery from the 1.7 percent revised annualized contraction in the October-December quarter, quashing fears that the economy would enter a technical recession, usually defined as two straight quarters of negative growth.
Much of the strength could be attributed to the leap-year effect, noted Kohei Iwahara, economist at Natixis Japan Securities.
"It may sound like a trivial issue but when you have one more day in February, that's 1.1 percent more days in the quarter so people are spending and eating more."
The domestic demand contribution to GDP inched up 0.2 percentage points thanks to higher spending on televisions and recreation, as well as food and beverage, noted a government official, Reuters reported.
But while personal spending was on the mend, consumer confidence remained soft overall and recent wage increases were disappointing, Iwahara said. The government's consumer confidence index fell 0.9 points in April on-month.