Someone said they have SC2 and no mod
 

I was reading on another board and someone said they burnt the japanese version and play it without a mod. Is that possible? Cause I didn't think it was or is.

Technically yes you can play a burned game without a mod if you have a v1-v6 system by doing the knife trick. You can also get a flip top case mod with swap magic discs. Both of these methods are total crap and it is recommended you don't use them. Just get a mod installed. Messiah 2 is best.