What is Kingdom Hearts?

Main character Sora sitting next to Donald Duck and Goofy.

Kingdom Hearts (キングダム ハーツ) is a series of crossover action role-playing games developed and published by SQUARE-ENIX (originally known as Squaresoft). It's a collaboration between SQUARE-ENIX and Disney Interactive Studios, and is under the direction of Tetsuya Nomura, a longtime SQUARE-ENIX character designer. Kingdom Hearts is a crossover of various Disney settings based in a universe made specifically for the series. The series centres on the main character Sora and his search for his friends and encounters with Disney, Final Fantasy and The World Ends With You characters on their worlds.

The series consists of seven games across multiple video game consoles, and future titles are planned. Most of the games in the series have been both critically acclaimed and commercially successful, though each title has seen varying levels of success. As of October 2013, the Kingdom Hearts series has sold over 20 million copies worldwide. A wide variety of related merchandise has been released along with the games, including soundtracks, figurines, companion books, novels, and manga series.

Kingdom Hearts merchandise.