Simple and Clean is the English-language version of Hikari, written and performed by Hikaru Utada as the theme song for Kingdom Hearts, first released in 2002. The game, a collaboration between Square and Disney, made the melody inseparable from its story of friendship and light versus darkness. As Kingdom Hearts grew into a long-running series, remixes, piano versions and short MIDI recreations circulated widely on forums, video sites and soundboards, keeping this brief motif alive as shorthand for early 2000s gaming nostalgia.