Janis was, up through eighth grade, best-friends with Regina George, until Regina started sharing rumours that Janis was a lesbian.
Janice is, along with her friends, Damian Leigh and Cady Heron, planning to mess up Regina George's life. Janis introduces Damian as "Almost too gay to function," and it was only OK when she says it. At the end of the movie, Janis eventually falls in love with Kevin Gnapoor, a Mathlete.
Janis is Lebanese, and has black hair and wears black makeup as she is presumably goth. It is said that in eighth grade, she cut off her hair.