The kiwi rose to ¥82.61 and earlier reached ¥82.68, the highest since May 2008, from ¥82.21 in New York on Friday. It slipped to US84.13c from US84.31c as equity markets fell in the wake of weak United States payrolls data.
BoJ governor Haruhiko Kuroda last week announced plans to double monthly bond purchases to about ¥7.5 trillion as he seeks to achieve 2% annual inflation in two years. Billionaire investor George Soros and Pacific Investment Management bond fund manager Bill Gross have both said the plan risked weakening the yen, Bloomberg reported.
''With the BoJ's game changer we can expect more strength in the kiwi against the yen,'' Mike Jones, strategist at Bank of New Zealand, said.
Mr Jones also expected further deterioration in US dollar sentiment after the Labour Department said payrolls increased by 88,000 workers in March against forecasts of 200,000 new jobs, adding to concern the world's biggest economy is experiencing a further bout of weakness.
Harbour Asset spokesman Christian Hawkesby said yesterday there were four main implications for New Zealand and global markets.
The move by the BoJ was yet another reason for global bond yields to remain relatively low, especially as bonds in the US, Australia and New Zealand were seen as a substitute for investors in the Japanese Government Bonds market.
The recent loss of US macroeconomic momentum and risks in Europe reinforced the theme of low interest rates. The US and New Zealand 10-year yields were now at their lowest levels in 2013, at 1.7% and 3.4% respectively. Low government bond yields provided further support to riskier asset classes, such as equities and credit, Mr Hawkesby said.
''In effect, policymakers are collectively trying to kick start economies by encouraging investors to provide more finance to credit an equity markets. Japanese investors may continue to search for yield in Australasia.''
The BoJ had become the new aggressor in the currency wars, providing yet another reason for the kiwi to remain elevated against its trading partners. The New Zealand trade-weighted index, the basket of currencies from the country's major trading partners, was near record highs, he said.
In the March Monetary Policy Statement, the Reserve Bank outlined that the TWI remaining elevated could cause it to cut the official cash rate from the current 2.5%.
If the recent actions of central banks were successful, at some stage investors would need to start looking for inflation protection, Mr Hawkesby said.
With the BoJ, the US Federal Reserve, the European Central Bank and the Bank of England all putting economic growth and job creation at the top of their agenda, they were being clear that they were willing to accept some collateral damage in the form of higher inflation.
''More generally, with the BoJ joining other major central banks in undergoing massive balance sheet expansion, they have joined the fight for a sustainable global economic recovery.''
However, by adding another layer of complexity, the BoJ also raised the stakes when it came time to navigate and exit from quantitative easing, Mr Hawkesby said.
The Nikkei 225 index at the Tokyo Stock Exchange, which gained 3.51% during the previous week, added 3.05%, or 391.58 points, to 13,225.22 in the first five minutes of trade on Monday.
The benchmark index then came back slightly to stand at 13,195.93, up 2.82% or 362.29 points.
Investors were cheering the weakening yen and its obvious impact on future corporate earnings, market players said.
Reuters reported while Japan's monetary barrage stole the show, it was the dismal turn in data from the US and Europe that brought home how this year was panning out worse than many had hoped.
News American employers hired far fewer staff in March than the gloomiest predictions managed to derail the heady rise of stock markets during the past few months. Business surveys from the euro zone confirmed the recession there was dragging on.
Hopes rested with China and signs of renewed vitality in the world's second-largest economy.
