Just watch your opponent carefully and don't just be reckless and rush down since Kasumi doesn't have the safety to do that without risks. Also Kasumi does have safe moves like 4H+K and 8P that are safe and have decent range so if you need something to help move those work too
Plus Kasumi is good at CH so rather than rushing the opponent down waiting for them to make a move so you can blow them up is also good. Kasumi has good defensive capabilities that can help balance her risky offense. Any player that says Kasumi isnt at all defensive as well offensive probably aren't playing that safe themselves
When i’m playing safe people say I need to be more aggressive. But when I am aggressive, people say i’m beind unsafe. The end result is that I will never be as good as the pros at this game. A friend who is newer than me is now better than me. I can’t break bad habits and now my win ratio is 54%.
Don't listen to what people say xD play who you like how you like, I've had people tell me time and time again that Kasumi isn't good at defense but I ignore them and do me while knowing what's safe amd unsafe and the range and situations attacks can be used from. A safe defensive Kasumi is A lot more dangerous than a reckless unsafe one who goes by speed and options rather than safety and observation
So here's a method (this is the ghetto and simple version). When you hop on training mode, turn on move details and look at -advantage-. Do stuff on block that's costing you matches.
Knowing this, you can prevent yourself from getting punished hard. In simple terms, if you are plus advantage (+1 and higher) it's safe to attack. If you are at disadvantage (-2 and lower) it's not your turn to attack. If you are hugely disadvantage (-8 and lower) protect yourself and expect someone to throw you.