I haven't tried to extract japanese files with Winzip, I only tried with WinRAR.
I read that it works with WinRAR and Bandizip, but if you find a way to change the language encoding or unicode or something on Winzip then you can try it.
If you find it very difficult or you can't unzip japanese files with WinRAR or Winzip configuration, the other way is to change system locale.
Also, where's the forum/site you got the download link?
Years downloading free games and apps made me double check what I'm downloading because I got hacked one day not-so-far ago, and not even Windows Defender detected it.
Downloding free stuff then was very different than downloading free stuff now.