As he begins to search for his missing friends, Sora is granted the mysterious Keyblade: the only thing capable of closing the gaps that the Heartless are using to invade the worlds. Sora is sucked through a portal and winds up in Traverse Town, a crossroads world that has become the refuge of those who have lost their worlds to the Heartless. This is until the day his world is engulfed by The Heartless, an eldritch species that feed on the hearts of innocent people and literally consume entire worlds. Sora is a young boy living a peaceful but boring life on an island with his best friends Riku and Kairi. The series is well-known for its incredibly bizarre premise and increasingly complicated plot, not to mention its increasingly absurd sequel subtitles. It's basically Final Fantasy meets Disney (along with some other Square Enix properties later on). Kingdom Hearts is a series of fantasy Action JRPG games, co-produced by Squaresoft (now Square Enix) and Disney, directed by Final Fantasy character designer Tetsuya Nomura, and starring characters from both companies.
So, a Square Enix developer and a Disney executive walk into an elevator. For the game in the series titled Kingdom Hearts, see Kingdom Hearts.