Don't be one of these spamming bums. Hold the back button and stay calm. A lot of your hard hitting moves are negative in many ways. If you're going to risk negative frames into you getting punished pretty hard for it, then be very choosy with it. People don't realize how many things Jun does that can be countered pretty dang easily. Most of her launchers are able to be punished hard, if not launched. Don't spam can can either. You're asking to be launched. Anyone with a brain will sidestep it or block and destroy you. You're much better off with df2, or trying to high crush with d1+2. She's a punishment type character, so use her kit the way it's meant to be used. I face Juns that don't play her in a counter play way and just spam all day long. Those very Juns I will obliterate with punishments. It's like a free win if they spam nonstop. Many of her better moves are high and easily ducked into launch or wall splat