The Nikkei share average fell 0.14 percent on Friday, posting its first weekly loss in five weeks, as Toyota Motor Corp and other recent gainers declined on concern about the outlook for the key US market. Softbank Corp tumbled on a brokerage price cut, while Sony Corp fell after a second recall of its batteries for notebook computers.
Investors were awaiting a speech by US Federal Reserve Chairman Ben Bernanke later in the day for information about the strength of the world's largest economy. "It's the end of the week and people are looking ahead to the speech by Bernanke, so I think investors are trying to close out their positions," said Tatsuyuki Kawasaki, director of equities trading division at Kaneyama Securities.
The Nikkei ended 21.96 points lower at 15,938.66. For the week it fell 1.04 percent, its first weekly loss since the five days to July 21. It had risen as high as 1.23 percent during the morning before falling steadily in afternoon trade.
The broader TOPIX index ended down 0.20 percent at 1,619.81.
Matsushita, the maker of Panasonic goods, dropped 0.8 percent to 2,475 yen, following a rise of 2.4 percent in the previous five sessions. Weaker-than-expected consumer price data had given the market some early support, convincing some investors that Japan may pause before raising interest rates again.
Japan's consumer price index for July came in showing a rise of 0.2 percent under a new calculation method, well below an economists' forecast of a 0.5 percent gain. Concerns that foreign investors were again pulling away from Japanese equities also weighed on the market.
Shares of Sony fell 2 percent to 5,000 yen after Apple Computer Inc said on Thursday it will recall 1.8 million notebook computer batteries made by Sony after nine devices overheated, causing minor burns to two users.
Top PC maker Dell Inc recalled 4.1 million Sony-made batteries last week, citing a similar problem with overheating. Softbank tumbled 9.7 percent to 2,140 yen after brokerage Lehman Brothers earlier this week lowered its target price on the Internet and telecoms firm to 900 yen from 1,125 yen, citing the amount of its debt.
Hisamitsu Pharmaceutical Co Inc plunged 12.7 percent to 3,370 yen after Phase 3 trials in the United States failed to show a significant difference between its Mohrus tape-type patch used to relieve muscle pain and a placebo.
After the news, Nikko Citigroup lowered its rating on the stock to "Sell/Medium Risk" from "Hold/Medium Risk" and cut its target price to 3,500 yen from 3,800 yen.
Trade activity was the slowest in a month, with 1.49 billion shares changing hands on the Tokyo exchange's first section. Declining shares beat advancers, 879 to 663.