* Nikkei up 0.7 pct on day, sheds 1.3 pct on week * Investors await G20 outcome, corporate earnings - analyst * Small-caps in demand, social game-related shares booming By Tomo Uetake TOKYO, April 19 (Reuters) - Japanese stocks rose on Friday in choppy trade after a downward trend in the yen helped offset negative sentiment from Wall Street and buoyed some exporters. Investors are keeping an eye on the meeting of officials from the Group of 20 leading economies and key corporate earnings for firmer direction. The Nikkei share average gained 0.7 percent to 13,316.48, climbing above its five-day moving average of 13,283.31 after moving in and out of negative territory in the morning session. But the benchmark still ended the week down 1.3 percent. On Thursday, U.S. stocks were dragged down by disappointing earnings forecasts by companies including eBay, while weak data added to worries over the recovery in the world's largest economy. Still, investors remained upbeat about Japanese equities as the yen slipped against the dollar on Friday after Japan said the G20 had accepted Tokyo's claim that the central bank's sweeping monetary expansion is aimed at beating deflation and not at competitively devaluing the yen. The comments by Japanese Finance Minister Taro Aso eased concerns that the bold monetary stimulus, which had triggered a drop in the yen to a four-year low versus the dollar last week, could come under criticism at the G20 meeting. "Investors are watching if Kuroda's comments are approved by international peers," said Masaru Hamasaki, senior strategist at Sumitomo Mitsui Asset Management. Bank of Japan Governor Haruhiko Kuroda said in Washington on Thursday that Japan's monetary easing was implemented for purely domestic policy reasons -- to achieve price stability and meet the country's 2 percent inflation target in two years and is not aimed at weakening the yen. "If all goes well with Japan not facing criticism of its aggressive monetary policy by its international partners, the yen may weaken further and large-cap stocks may be bought," said Yoshiyuki Kondo, an analyst at Daiwa Securities. The dollar last traded at 98.64 yen, moving a tad closer to a four-year high of close to a 100 yen last week. This provided a tailwind for some exporters. Mazda Motor Corp, Nikon Corp and Sony Corp advanced between 1.7 percent and 2.3 percent. "While foreign investors cautiously await the outcome of the G20 meeting and key corporate earnings, retail investors are actively trading medium-to-small stocks," said Yuya Tsuchida, a strategist of Toyo Securities. "The underlying trend is solid. Next week, once the major events are over, I think the Nikkei may test the 14,000 level, depending on how sound key corporate earnings results will be," he said. The quarterly earnings season will kick into high gear starting next week. The broader Topix added 0.3 percent to 1,126.67, with 3.59 billion shares changing hands, the lowest in 12 sessions. The benchmark Nikkei has gained more than 50 percent since November when Shinzo Abe, who became prime minister in December, called for bold fiscal and monetary expansionary policies to revive the economy and end stubborn deflation. Societe Generale said the most-traded Nikkei stock option on Friday was a call with a strike price of 14,500, 8.9 percent above the current level, and with a May expiry. The next most-traded was a call at 14,750, followed by another call at 14,250 and a put at 12,250. GAME TIME Social game-related stocks emerged as clear gainers this week. "The trigger appears to have been KLab's 'Lovelive' game. This could be another boom," said Hiroshi Yamashina, an Internet-sector analyst at BNP Paribas Securities in Tokyo. KLab Inc's 'Love Live! School Idol Festival' game rapidly climbed up the rankings after its launch on Tuesday and that captured the market's attention, Yamashina explained. KLab's stock price shot up 68 percent over the last four sessions. The share closed 5.8 percent higher on the day. Colopl Inc, which has been dubbed as the "next GungHo (Online Entertainment Inc )", rose 46 percent over the last four sessions. It added 1.4 percent on the day. Capcom Co Ltd jumped 9 percent on Friday after the gaming company said it would buy back 1.5 million shares, which amount to 2.6 percent of its outstanding shares and worth up to 2.5 billion yen ($25 million), between April 22 and May 31.