Kingdom Hearts is the first game in the Kingdom Hearts series. Revolving around a fourteen-year old boy named Sora, it details his adventures after his homeworld is destroyed by sinister creatures known as the Heartless, and his attempts to restore his world and reunite with his friends. In the process, he meets many characters from classic Disney films and a handful from the Final Fantasy video game series. The main theme song for the game is "Simple and Clean", performed by Utada Hikaru. Chronologically, Kingdom Hearts follows Kingdom Hearts Birth by Sleep, takes place during Kingdom Hearts 0.2 Birth by Sleep -A fragmentary passage- and takes place before Kingdom Hearts Chain of Memories, as well as partially overlapping with Kingdom Hearts 358/2 Days.