The economy expanded an annualized real 1.5 percent in the April-June quarter, better than the initially reported 0.4 percent thanks to a boost in corporate capital investment, government data showed Friday.

Despite the improvement, the economy still grew at a slower pace than in the previous quarter amid the diminishing effects of fiscal stimulus, and government officials expressed caution about the future outlook.

"The direction that the economy is picking up has not changed," Satoshi Arai, state minister for economic and fiscal policy, told a news conference. Finance Minister Yoshihiko Noda made similar remarks.