It's difficult to know what to advise without knowing the model of Mac and version of Mac OS X it's running. If you can provide any sort of clues as to the model of Mac - there should be a model number of it somewhere, or you can determine the model by entering the serial number on this web page:
From that information we can at least make a guess as to the version of OS X it may be running and direct or advise you properly from there.
Jerry Jay wrote:
A friend imported an apple desktop machine which when i turned it on, everything shows in Japanese
If you can see a gray icon with a gear wheel in it in the dock, click on that.
If you can then see an icon with a blue UN flag, click on that.
Click on the leftmost tab.
In the list that appears, click and hold on English and drag it to the top of the list.
Restart the machine.