The head of the Bank of Japan today hit back at claims it is manipulating the yen, saying the BoJ’s monetary easing was solely aimed at stoking economic growth at home. “Our purpose is not to guide exchange rates, but to overcome deflation in the near term and bring about sustainable growth with price stability,” Shirakawa told a news briefing here. The issue is expected to top the agenda at a group of twenty (G-20) meeting in Moscow that starts Friday amid talk of a “currency war” in which rival nations drive down their currencies to protect their exporters.