Quick definition: "Kawaii" - Japanese for "cute" or, more accurately, "AAAwww" - the kind of thing you say when you see something sweet like Pikachu, or "Hello Kitty", or perhaps a small friendly moomin!
So to describe something as kawaii can mean that it's
- japanese, big eyed manga / anime
- from the cartoon world
- stylised with bright colours
- fun and funny!