SoKeefe

SoKeefe is the het ship between Sophie Foster and Keefe Sencen from the Keeper of The Lost Cities fandom.

Keeper of The Lost Cities
Sophie and Keefe meet in the first book, when Sophie messes up her alchemy in Level Two, burning Lady Galvin's cape due to misreading the instruction "WHAP" as "whip". Keefe is ditching his Level Four Universe, due to Lady Belva having a crush on him. Sophie feels that he is joking, but thinks he's also very good looking, and that half the girls at school have a crush on him. She needed help going to the Healing Center, as she was going the wrong way, and Keefe takes her with him there. She even thinks that he is cool and cute.

When meeting Lord Cassius, Sophie feels sad for Keefe, having to go to a cold and critical father everyday. She is also glad when he is back to his old self without his father around. In detention, he tries to grab her as his partner when ballroom dancing, until Lady Belva takes him for herself and pairs Sophie up with Valin. Keefe suggests at a sleepover party with Fitz and Biana that the girls could braid each other's hair and giggle about boys when they were at it, then suggesting that it would be a good idea to find out some boys that Sophie would like, to which she blushes. She also blushes when he calls her "the mysterious new girl".

During the ceremony, Keefe gives Sophie a pack of Mood Candy, because "it would always taste bitter if she didn't relax." The note also tells her to stay out of detention. After finding out the truth why Biana wanted to be her friend, Fitz and Keefe try to comfort her, and Keefe suggests that she be left alone, his eyes wondering if she would be okay, showing his concern for her. They meet under the Leapmaster, and Keefe says that he would see her again. At the end of the book, Keefe is revealed to be the one who told Fitz and Biana about the Four Seasons Tree, and almost says that she would have died if he hadn't told them, but cuts off, as he didn't want to talk about her dying.

Exile
Keefe smiles and laughs at Sophie, joking about her habit of always keeping secrets, claiming it's "how she keeps her sense of mystery". Before coming late to meet her, he excuses how he was late to fix his hair, saying that he had to look good for the ladies, referring to Sophie, which shows that he has some attraction towards her.

Grady sends Keefe to look after Sophie when she offers to fly with Silveny the alicorn to the Black Swan's hideout, so that she can get her abilities fixed, as he would rather her go with someone other than let her go by herself, and also because Keefe is the only one besides Sophie that Silveny is comfortable with. Keefe accepts, and it is shown before that Sophie accepted that Keefe help her with her problem, thus forming Team Foster-Keefe, being dubbed by Keefe. On the flight, Keefe leans very close to Sophie and tells her that even though he makes a lot of jokes, he really cares about her and promises her that he would take care of her. He even takes her hand and encourages her by saying there is absolutely nothing wrong with her.

Everblaze
When Sophie feels that they are trapped in the void due to her teleporting, and loosing focus, Keefe comforts her and attempts to help her. Later on, when she asks him if his dad, Cassius has hurt his mother, Gisela, he says that it was nice to know that she cared, going by her nickname the Mysterious Miss F. She even holds his hand and comforts him when he wonders if his parents are really worried about him. He is also shown to admire how smart she is, and even calling her cute, which makes her blush and hide behind her hair. When the two think that Cassius is the one who is the leader of the Neverseen, Sophie tells Keefe that she would never hate him, and that he would never be like his father.

Fanon
SoKeefe, out of all of the other ships, is shown to be shipped by many people. It is also revealed that one of Shannon Messenger's editors ship Sophie and Keefe. In other words, it is the most popular ship in the entire franchise, and the most written ship for both. It is also the most popular ship for both characters.