SoraXKairi or SoKai (Japanese ソーラカイリ Sora Kairi) is the term used to refer to the romantic relationship between the two somebodies Sora ソーラ and Kairi カイリ
Sora is the main protagonist in the Kingdom Hearts series, as well as a Keyblade wielder. He is an upbeat teenager who may seem simple-minded at times, but is very aware of the importance of his quest. He possesses a strong sense of justice and an unrelenting heart. At times, he is impulsive and quick to anger when defending his friends, but he is always sincere about what he says and does. He has been best friends with Riku and Kairi since he was a small boy.
Sora has a typical brave and heroic personality, meaning he'll willingly risk his life for people he doesn't even know yet, as shown when he tries to save Ansem the Wise from the explosion, to no avail. He's extremely loyal to his friends, and has been shown to be extremely forgiving to Riku (even forgiving Riku for the times he has tried to kill him), and is highly protective of Kairi. He constantly thinks positive and is therefore highly optimistic. Throughout his journeys, he readily puts aside his own personal goals to help those in need.
Kairi is one of several original characters appearing in Kingdom Hearts, and is also one of the main characters in the series. She is the original persona of Naminé. Kairi was born in Radiant Garden and currently lives on Destiny Islands along with her two best friends, Sora and Riku.
Kairi is caring, kindhearted and not afraid to speak her mind. However, she is determined and courageous when someone she cares about is in danger, often risking her own safety to help that person. She's also become slightly more withdrawn because of Sora's absence, having obtained wisdom usually beyond someone of her age. She's not as brash and bold as she was in the first game, but she's still pretty sociable.
Their RelaitonshipEditThroughout the games, Kairi is revealed to have feelings towards Sora but then Kairi greatly admires Sora and Riku for their ability to get stronger, and seeks to become stronger herself. When Sora first sets out on his adventure, he is obsessed on finding Kairi and Riku which changes over time to protecting the many worlds. At the very begining, Riku and Sora talk about a fruit on their island that when eaten between two people means the two would be bonded together, it is hinted that Sora wanted to share it with Kairi, which was proven at the start of Kingdom Hearts when he drew himself giving Kairi the Paopu Fruit in one of their cave drawings
Later on, Sora turns into a Heartless, it is Kairi's heart that saves him, brings him back to himself.
Being the one of the only two girls on the island, it is likely that Sora has romantic feelings towards Kairi, considering the hints that were given in Kingdom Hearts 2, when he was teased by Donald and Goofy when he was fantasizing about Kairi, while watching other pairings in their intimate moments.
During Kingdom Hearts 2, Organization XIII, used Kairi as bait to force Sora into defeating the heartless, this led to Sora confessing to Saix, that Kairi meant more to him than anyone, further hinting in his potential feelings towards Kairi.