Japan's economy expanded at its fastest pace in a year in January-March as business investment rose slightly, but goods piling up in factory warehouses posed a potential challenge to policy makers seeking to vanquish years of deflation.
Private consumption, housing investment and exports all rose but at a feeble pace, leaving Tokyo with more work to do two years after a radical monetary stimulus program has brought only scant success.
"The growth number may look good on surface but there's not much to cheer about," said Yoshiki Shinke, chief economist at Dai-ichi Life Research Institute.
The world's third-largest economy expanded at an annualized rate of 2.4 percent in the first three months of this year, beating a median market forecast for a 1.5 percent increase and a revised 1.1 percent expansion in October-December, data from the Cabinet Office showed on Wednesday.