Japan's Nikkei Stock Average retreated from yesterday's gains and tumbled on Friday as Yen appreciated versus US Dollar after data showed unemployment claims in US declined to a four-year record low. Nikkei 225 index lost 1.14% or 115.61 points and closed at 10,011.47. Export shares were most harmed by the strengthening Yen. Honda lost 2.9%, Sony lost 3.1% while Toshiba gave up 2.7%. Tokyo Dome rallied 5% after Mitsubishi UFJ Morgan Stanley Securities upgraded its target price citing faster than expected recovery.