Rachel Seo Jenny Han’s 2014 novel “To All the Boys I’ve Loved Before” first introduces readers to Kitty Song Covey as the mischievous younger sister of main protagonist Lara Jean.
Kitty, a precocious pre-teen, harbors a penchant for instigating drama — an affinity that sets off the chain of events leading to the fake-but-eventually-real relationship between her sister and love interest Peter Kavinsky.
Memorialized by Anna Cathcart in the 2018 film version of the book — which spawned two sequels and launched the careers of Lana Condor and Noah Centineo, who played the leads — Kitty often serves as the comic relief, offsetting Lara Jean’s careful romantic idealism.
But in spinoff series “XO, Kitty,” which premiered on the streaming service on Thursday, the little sister becomes the star, and Cathcart steps into the spotlight.