A phrase said in short for Totally Cute ~ (Kawaii is Japanese for "cute" - pronounced ka-wa-ee).
Originated in Sydney, Australia by a group called the Totes Kawaii group - a group of anonymous people who befriended each other at a maid cafe interview.
Girl 1: "OMG! Look at that lolita dress!"
Girl 2: "Aww it's totes kawaii~"