Because you like Martha Jones in Doctor Who
If you need her, Lisa Simpson will be in her room with her saxophone and a good book. See them in The Simpsons.
Shrek is a nasty-on-the-surface ogre with a heart of gold and an earful of wax. See them in Shrek.
Clementine Kruczynski thinks that too many guys think she's a concept, or she completes them, or she's gonna make them alive. See them in Eternal Sunshine of the Spotless Mind.
Edward Elric has a quick mind along with a quick temper. See them in Fullmetal Alchemist.
A brilliant "extractor," Dom Cobb has spent the past few years running from the authorities and his inner demons. See them in Inception.
Leslie Knope can accomplish anything, literally anything, with a little grit and help from her office. See them in Parks and Recreation.
Cassie Sullivan is resilient and resourceful, but she's not quite as brave as she pretends to be. See them in The 5th Wave.
It turns out the girl of your dreams just might have dreams of her own. See them in (500) Days of Summer.
Carrie Bradshaw is a sex columnist addicted to expensive shoes, Cosmopolitan martinis, and unavailable men. See them in Sex and the City.
Castiel might be an immortal angel, but the human world is still more than a little confusing. See them in Supernatural.