Strategy
Neutral
Kaori's biggest weakness is that she suffers from a very linear footsie game, due to poor reach on most of her grounded buttons, and a series of aerial buttons that aren't really all that different from each other. However, she's blessed with a fantastic fireball and a highly-rewarding anti-air normal in cr.HP, so a lot of her neutral will be based around using these two tools, forcing space control her fireball and swatting people out of the air if they try to move around it. For jump angles that cr.HP can't catch, try more unorthodox methods of punishing jump-in attempts, like throwing another fireball, or making the opponent eat an instant super during their landing recovery.
Offense
Once you've restricted the opponent's movement and pushed them to the corner, you can open up your offense by applying stagger pressure. The main way Kaori will be opening people up is through frame traps mixed with throw/Ryuurentai, and catching chicken-block attempts from the opponent with f+HP and cr.HP. You can very easily start this up by applying normal strings cancelled into LK Ressenshuu, as the frame situation here is very good for you. You'll have a very easy time locking people down once you get going, so make sure you're ready to capitalise on the opponent's defensive mistakes.
Defense
Kaori's most reliable defensive options are EX Ressenshu and Retsuzandou, which are costly, but highly reliable.
