Passion (Hikaru Utada song)

"Passion"
Single by Utada Hikaru
Released	December 14, 2005
Format	CD DVD digital download
Recorded	2005; Westlake Audios Studios (California, United States) Bunkamura Studios (Tokyo, Japan)
Length	4:44 (Album version) 4:27 (Opening version) 5:58 (After the Battle)
Label	EMI Music Japan Eastworld
Songwriter(s)	Utada
Producer(s)	Utada Akira Miyake Teruzane Utada
Utada Hikaru singles chronology
"You Make Me Want to Be a Man" (2005) "Passion" (2005) "Keep Tryin'" (2006)
"You Make Me Want to Be a Man" (2005) "Passion" (2005) "Keep Tryin'" (2006) Alternative cover English cover for "Sanctuary"

"Passion" is a song recorded by Japanese singer Utada Hikaru, taken as the fourth single from her studio album Ultra Blue (2006). It premiered on December 14, 2005, in two physical formats and for digital consumption, distributed by EMI Japan and EastWorld. "Passion", alongside its English counterpart "Sanctuary", were used as the national and international theme songs to the Square Enix video game Kingdom Hearts II (2006); both tracks serve as the successor to "Hikari", which is found on the games first instalment.

The games creator, Tetsuya Nomura, sought to collaborate with Utada once again as he felt she was part of the franchise's family, alongside his prospects for her to break foreign and international markets. The conception of the two tracks were to emphasize a "dusk"-like vibe to the game, in comparison to "Hikari" which she described as the "dawn". Musically, "Passion" has been described by music commentators as a multi-genre tune, noting elements of alternative rock, ambient and ethereal music. The song's lyrics delve into themes of nostalgia, and discuses the circumstances of past, present and future.

Upon its release, both songs garnered critical acclaim from music critics, who strongly opined her musical departure and the singers progression in production and singing. Additionally, several publications ranked the songs on their year-end lists of 2005–06 and soundtrack lists. Commercially, "Passion" experienced success in Japan, peaking inside the top ten on the Oricon Singles Chart and TBS's Count Down TV chart; despite this, "Passion"'s sales were much lower than her previous releases. Nevertheless, it was certified Gold in three categories by the Recording Industry Association of Japan (RIAJ).