Seth x Summer

Seth x Summer is the het ship between Seth Cohen and Summer Roberts from The O.C. fandom.

Canon
Presumably Seth and Summer meet as schoolmates since childhood. Seth falls in love with Summer with her upon hearing her read a poem that everyone believes she wrote to their class. Seth remains in love with Summer all his life and always looks at her remembering everything about her and feeling bad when she doesn't come to his Bar mitzvah.

Seth remains in love with Summer all his life, but never finds the courage to try to woo her, so when they reach adolescence, even though they attend the same high school, Summer doesn't even know about Seth's existence, let alone his feelings for her.

At one point Seth gets a sailboat he calls Summer Breeze in Summer's honor.

Ryan's arrival
Seth's father Sandy Cohen is a public defender and one of his clients is a boy of Seth's age, Ryan Atwood who tried to steal a car with his brother. Sandy manages to get him released, but Ryan's mother Dawn is totally unable to take care of him, so much so that when her partner throws Ryan out of the house, she doesn't even object that much. Ryan has nowhere to go and therefore can not help but ask Sandy for help who had recommended that he call him in case of need and the man, not having the heart to leave him in the middle of the street, decides to take him to his house for the weekend.

Seth is a lonely, introverted boy, comic-book addict and not athletic, so he has no friends, but he and Ryan make friends almost immediately. Seth talks to his new friend about his crush on Summer and indeed Ryan's arrival changes his life forever, as Seth's neighbor and best friend of Summer's Marissa Cooper is immediately impressed by Ryan and invites him to a party he takes Seth with him to.

Summer is also immediately attracted to Ryan, and when he finds out Seth is upset, but shortly after the young Atwood helps him against bullies. When Sandy brings Ryan back to his mother, the two find the house deserted and so he decides to keep Ryan at home for a while longer.

Fanon
Seth x Summer is one of the most popular ships of The O.C. . Even though they both dated other people throughout the show it was always clear that they never stopped loving each other. It rivals Ryan x Marissa and Rylor as the show's most popular ship.

There are numerous videos and fanfictions dedicated to this couple.

Fan Fiction
Seth/Summer on Fanfiction.net