* Nikkei gains 3.9 percent on the week * DeNA soars on strong results, pulls up Gree * Sony firms on So-net purchase * Sharp scrambles back up 9 pct on short squeeze By Sophie Knight TOKYO, Aug 10 (Reuters) - Japan's Nikkei share average fell on Friday as investors lacked fresh incentives to buy, but the index still marked its biggest weekly gain since February following a four-day rally spurred by hopes for more global stimulus. The Nikkei lost 1 percent to 8,891.44 points but advanced nearly 4 percent up on the week, its biggest gain since mid-February, after surfing a wave of short-covering triggered by better-than-expected U.S. jobs figures last week. Online gaming company DeNA Co Ltd soared 22.1 percent, its biggest-ever one-day jump, on strong results, while Sharp Corp scrambled up 9.4 percent on a short-squeeze after dropping as much as 34 percent early this week after revising down its full-year guidance. "This week's rally was entirely fueled by speculation of stimulus, so concern about a global slowdown retreated," said Yoshihiro Ito, chief strategist at Okasan Online Securities. "But now people are beginning to question what's coming up, and with the holidays and a poor earnings season the Nikkei lacks the power to pierce 9,000." However, analysts said that the risk aversion that reigned through July was ebbing as disappointing data from China and the Bank of Japan's refusal to budge on policy on Thursday only spurred hopes for further easing in the imminent future. "Nothing is actually improving but the bad state of the U.S. and Chinese economies is priced in now," said Ryota Sakagami, chief strategist of equity research at SMBC Nikko. "If data shows things aren't as bad as assumed then it's a plus, and yet if they're worse than assumed people expect easing or stimulus, which is also a plus." Amid a weaker market on Friday, a handful of companies saw gains on the back of strong results as Japan's earning season drew to a close, including Taiyo Yuden Co Ltd, which climbed 10.3 percent af t er its earnings beat expectations. DeNA Co Ltd jumped after its solid quarterly results calmed fears that revenue had been hit by the withdrawal of its lucrative "complete gacha" game due to pressure from regulators. The news helped competitor Gree Inc gain 8.1 percent. Japan's quarterly earnings season has been relatively weak, with 53 percent of the 142 Nikkei companies having undershot market expectations, compared with 40 percent in the previous quarterly earnings season, data from Thomson Reuters StarMine showed. Yamada Denki Co Ltd bounded up 7.9 percent despite posting a 73.8 percent year-on-year decrease in operating profit for the April-June quarter, as brokerages said sales had been distorted due to the switch to digital from analogue televisions. "With the earnings season now over, investors will be looking to the economic indicators out next week as a measure of business confidence," said Masayuki Doshida, senior market analyst at Rakuten Securities. The Bank of Japan cut its assessment on exports and output on Thursday as Japanese firms feel the pressure from slowing global growth, but followed the U.S. Federal Reserve and the European Central Bank in deciding to hold fire on policy changes. The broader Topix dropped 0.7 percent to 746.79. SONY TO PICK UP SO-NET Sony Corp ended up 2.7 percent after climbing as much as 5.6 percent after it said on Thursday it plans to buy all the shares it does not already own in So-net Entertainment , an internet provider and medical information website operator, for about 60 billion yen ($765.70 million). So-net shot up 21.1 percent to 402,000 yen, while the news also awarded a 6.5 percent gain for M3 Inc, a marketing company and a listed subsidiary of So-net. Against the strength of competitors DeNa and Gree, Japanese online game provider Nexon Co Ltd sank 24.5 percent after the company cut its full-year operating profit guidance by 9.9 percent to 47.1 billion yen.