The Bank of Japan's Tankan survey released Monday showed the confidence index among big manufacturers including automakers moved to the plus side for the first time in the past seven quarters.
The Tankan survey measures the difference between the percentage points of companies reporting favorable business conditions and those reporting unfavorable conditions.
The Abe government, which came to power this year, has put in place a number of economic policies and stimulus measures to lift the world's third largest economy out of its years of deflation and boost exports by weakening the yen.
The effort seems to have paid off, with the latest Tankan survey showing a huge turnaround from the January-March quarter's minus 8. The index was plus 6 in the January-March quarter of 2011.
Japan's economy grew at an annual rate of 4.1 percent in the first quarter.
The Financial Times reported that a 20 percent drop in Japan's trade-weighted currency has helped raise the optimism of companies and other sectors of the economy.
"We see a firm recovery in consumption as the stronger corporate outlook on the economy manifests itself in larger summer bonus payouts," Naohiko Baba, chief economist at Goldman Sachs in Tokyo, told the Times.