By Leika Kihara and Kantaro Komiya TOKYO (Reuters) – The Bank of Japan maintained ultra-low interest rates on Friday and vowed to defend its cap on bond yields with unlimited buying, bucking a global wave of monetary tightening in a show of resolve to focus on supporting a tepid economic recovery. The yen fell as much as 1.9% and bond yields fell after the decision, which was widely expected but disappointed some market players who speculated the BOJ could give into market forces and tweak its yield cap policy. However, in a nod to the hit that the yen’s recent sharp declines may have on the e…