The Japanese central bank decided to maintain its monetary policy unchanged at a policy board meeting led by Gov. Masaaki Shirakawa on Thursday, leaving space for an aggressive monetary policy expected to be applied in order to boost the economy. The Bank of Japan will keep the loan rate in a range of 0.0%-0.1% with the size of the bank's asset-purchase programme at Y101 trillion ($1.08 trillion) by the end of 2013.