The movie deals with casually intertwining stories of the heart that take place over the course of one Valentine's Day.
An on-leave army officer named Kate is a passenger on a flight from Iraq to Los Angeles when she meets Holden, a gay man whose lover is a closeted football player. The owner of a florist shop, Reed proposes to his girlfriend, Morley, while learning his best friend, Julia, has a boyfriend named Harrison who turns out to be married. An assistant named Liz is working at the biggest talent agency in town and is dating the mailroom assistant, Jason. Julia's mother, Estelle is a happy retiree who must reveal an affair from long ago to her husband, Edgar, but for their granddaughter is going to have sex with her boyfriend at her high school, in which Tyler Harrington and Samantha Kenny who also go there are athletic teenagers who are deeply in love.
Meanwhile, a publicist named Kara is seemingly alone with no date on Valentine's Day working for her boss Kelvin Briggs whom she falls in love with working together. Oscar-winning actress Kathy Bates makes an appearance as a "love therapist." Joe Jonas voices the dog of Alba's character Morley.