In the week to April 22, the headline Nikkei index gained 0.95 percent, or 90.69 points, to 9,682.21. The Topix index added 0.11 percent, or 0.89 points, to 842.18.

"Stocks are likely to be stuck in a narrow range amid the lack of clear direction," said Tsuyoshi Segawa, equity strategist at Mizuho Securities.

"The biggest concern of the market is the impact of the quake and tsunami on Japanese firms' earnings forecast for the current business year and later," he said.

Japanese firms start to announce their earnings next week, although the releases will be concentrated after the Golden Week holidays through early May.

"The market has been stabilising amid the nation's restoration process from the disasters, although worries linger over the crippled nuclear plant," Segawa added.

Global stock markets were roiled by ratings agency Standard & Poor's warning Monday that it may downgrade US sovereign debt, focusing attention on the problem of debt-ridden economies around the world.

But the Tokyo market was buoyed later in the week by upbeat New York stocks on the back of strong US corporate earnings.

"After the market has been driven by stronger-than-expected US corporate earnings, US monetary policy and macroeconomic data will be important for the next direction," said Kenichi Hirano, general manager at Tachibana Securities.

The Federal Reserve will hold a monetary policy meeting next week, with its chief Ben Bernanke scheduled to hold a news conference on Wednesday.

The Bank of Japan plans to hold a policy meeting on Thursday and release a semi-annual report on its economic and price outlook.

The market is also closely watching Japan's industrial production data for March, which is due out on Thursday, after manufacturers' supply chains were disrupted by the March 11 disasters, brokers said.