The yen fell against a basket of currencies, and particularly versus the US dollar, on Friday.
That followed a co-ordinated intervention by central banks from the Group of Seven – the world’s richest nations – the first time in more than a decade they have done that.
The move was to calm global financial markets after a tumultuous week.
Japan’s Finance Minister Yoshihiko Noda said: “Today, along with others [from the G7], we decided to conduct a joint intervention in the foreign exchange market. Extreme fluctuation in currency rates is not good for the stability of financial markets and also the economy.”
As the Japanese currency soared after the earthquake, tsunami and nuclear crisis, the dollar slipped to a record low of 76.25 yen on Thursday. After the G7 intervention the dollar surged with one dollar worth almost 82 yen.
Japan’s Nikkei share index ended up 2.7 percent on Friday recouping some of the week’s huge losses.
It had fallen just over ten percent during the week, wiping the equivalent of 247 billion euros off the value of Japanese companies.