One of the central themes in Every Summer After is that friendship is the starting point for and foundation of love. Fortune incorporates the romantic fiction trope of soulmates by presenting Percy and Sam as each other’s one true love. Because the two meet when they are children, they first develop a strong friendship that then evolves into romance over the years. However, the thread of friendship continues to be strongly interwoven throughout their relationship, and they continue to enjoy the activities that they first bonded over platonically, like swimming and watching horror movies.

Percy first meets Sam at a time when she is young and vulnerable. She is dealing with what appears to be the end of several friendships, after Delilah ostracizes her from their girl group at school. Even Percy’s father notes that she could use a friend. Percy has a space in her life that Sam steps into, and the situation is primed for him to become an important presence in her everyday existence. Percy’s readiness to make friends with Sam is compounded by his immediate and easy acceptance of everything about her, from her physical appearance to her interests and hobbies. Sam’s request for a friendship bracelet contrasts with Delilah and the other girls’ destruction of their bracelets, emphasizing that Sam’s friendship comes at a time when Percy is isolated from her peers.