Meaning "cute" in Japanese, Kawaii is an aesthetic that revolves around everything that is innocent and, you guessed it, cute! The aesthetic carries a lot of pastels and light colors, but It can be dark too.
(Badtz-Maru from Hello Kitty is a great example. Plus there are darker subcategories of Kawaii too!) There's actually some interesting history behind Kawaii, which I recommend reading up on.

Lots of food and candy within this aesthetic as well. This hangs on too anything that is too cute to boot.