The Nikkei ended slightly lower on Friday in thin trade, bringing its weekly loss to 0.8 percent, as investors awaited more signals from leaders working out the details of a plan to contain Europe's debt crisis.
Germany and France released a statement on Thursday saying that European leaders would discuss a global solution to the crisis on Sunday but no decisions would be adopted before a second meeting to be held by Wednesday at the latest.
The focus of trading next week will be the European meeting and its outcome, and until then, investors are unlikely to want to take new positions, said Takashi Ushio, head of the investment strategy division at Marusan Securities Co.
The Nikkei .N225 slipped 3.26 points, or 0.04 percent, to 8,675.60. The broader Topix index .TOPX lost 0.2 percent to 744.21, dropping 0.6 percent for the week.
Volume was thin, with only 1.32 billion shares changing hands on the main board, below Thursday's full-day volume of 1.46 billion. Decliners beat advancers 847 to 628.
Strategists said the Nikkei has major support at its 25-day moving average at 8,657, while its five-day moving average around 8,750 is seen as immediate resistance. But those levels might go untested until Wednesday, pending any new European developments.
Shares of scandal-hit Olympus Corp ended down 6.8 percent at 1,231 yen, their lowest close since December 1999.
Olympus shares have lost 50.4 percent of their value, or 340 billion yen, since the company fired British chief executive Michael Woodford from his top post a week ago.
On Thursday, the company's biggest shareholders called on the precision instrument maker to explain hundreds of millions of dollars in controversial payments publicized this week by Woodford.
But beleaguered utility Tokyo Electric Power Co topped Olympus in turnover, bumping the manufacturer off the top position it had held for five trading sessions.
Tepco shed 9.9 percent to 263 yen as some investors took profits after shares of the operator of the crippled Fukushima Daiichi nuclear plant spiked 36 percent on a late surge in the previous session.
The utility's shares have been prone to sharp market moves since the March 11 earthquake made the utility potentially liable for billions of dollars in compensation claims from radiation victims.
Mitsubishi Motors rose 1 percent to 100 yen after the Nikkei business daily reported the car maker's operating profit likely quadrupled on the year to around 28 billion yen in the April-September first half, beating its earlier forecast for 18 billion yen.
Trend Micro rose 1.9 percent to 2,697 yen, its highest since late February, helped by expectations that the increasing popularity of smartphones using Google's Android platform will lead to growing demand for the company's antivirus services.