If it's just ICQ having set itself to 'Japanese' as the default language, then I'll try explain what might sort it out....
When you open up ICQ, there should be two pieces of text just below the ICQ logo, and above the area where your profile/picture are (in English the text is Main and Contacts, no idea what they look like in Japanese!)
The one on the left (Main) will open up a list, you want the fourth one down in there (Options), which in my ICQ has a picture of crossed screwdriver/spanner next to it.
That opens up a lot more options in a pop-up window, the first tab of those (Customization in English) has four options below it, you're after the second one down 'Tweak my ICQ' - strange graphic next to it, to me it looks like a slowly wilting flower!
Click on that, you should see a panel with four main sections in it, the top two have pull down menu lists - the second of those is where you choose your language, hopefully like mine the list shows the languages in their own character sets...
Once you have chosen 'English' you get another popup screen, click on the left of the two buttons to 'OK' your changes, ICQ should restart in English...
Hope that helps, rather than adding to the confusion
