Is anything else besides the game blurry? It could be that your display and/or graphics settings were/have changed somehow.

only the game, thus the image

Hm weird. Only thing I could suggest would be clearing the game's cache. And by that I mean going to your users/[username]/appdata/roaming folder and finding the "naruto online" folder and at the least putting it in the recycle bin, then relaunch the game. Fair warning this will cause you to have to relogin completely and it will have to redownload the game files it cached before.

Hello,
As the previous poster indicated, this is usually a result of a resolution setting that is incompatible with the game. Can you please try adjusting your device's resolution settings to see if the issue is resolved at a different resolution?
Thanks!

Still blury, got a new Samsung full HD Monitor.
What is the best resolution for the mini client game? in pixels?

I mean Right now I am in the mini client forum and it is all perfect!

Hello,
As mentioned before this will likely vary based upon your specific device and settings. Please try multiple resolution settings to see which ones work for you.