With the promise of nothing but fun in the sun, Zinnia, Fay, Kiara, and Valentina are all geared up to reconnect on their 10th annual girls' trip that brings them together from all different cities. What they don't know, however, is that some baggage comes on vacation whether you pack it or not. Their outside lives slowly seep into their seaside getaway, and when the weekend proves to be a series of secrets, snide remarks, and non-stop bickering, tensions escalate. Suddenly they are all forced to wonder: Have they outgrown their childhood friendships? Shedding light on the power and complications of lifelong friendships, This Is Why I Need You questions the choices we make in life that can bring us closer together - or pull us further apart - from people we need most: our friends.