Kyou's route intertwines with Ryou's route. Basically Kyou has had a crush on Tomoya for years now, but Ryou wants to openly admit it to Tomoya. So Kyou, being the kind soul that she is, tries to get Ryou and Tomoya together, despite the fact that Kyou has loved you for far longer.
Then skip a few hours of Tomoya and Ryou going through an awkward dating phase, Kyou almost kissing Tomoya, and Tomoya eventually realizing that Kyou loves him more, Kyou cuts her hair and tries to make sure that Tomoya really loves her more than Ryou. Tomoya thinks Kyou is Ryou, he confesses, Kyou kisses him, quick end with short-haired Kyou and Tomoya hugging each other.