"Passion" is a song recorded by Japanese-American singer-songwriter Hikaru Utada, taken as the fourth single from her studio album Ultra Blue (2006).

The creator of the Kingdom Hearts franchise, Tetsuya Nomura, sought to collaborate with Utada as she previously wrote "Hikari", alongside his prospects for her to break into foreign and international markets.

An accompanying music video was directed in China by her then husband Kazuaki Kiriya, which depicts Utada in a dreamscape filled with animated clouds, figures and a cathedral-like architecture.

Since its release, "Passion" and "Sanctuary" have been widely considered as two of the best songs in video game history and has been recognized as a major factor in Utada's commercial rise in the western market.

[2] But scheduling time with Nomura proved to be difficult, as Utada worked on her second English language album Exodus in her hometown New York City; she had been signed to Island Def Jam the previous year as their headquarters discovered her success in Japan.

[3] Kingdom Hearts II was publicly announced in July 2005, and Nomura confirmed Utada's second involvement with the series, "When we were creating the original game, there were a lot of factors that were influenced by Utada-san's theme song.

[5] Regarding the song's concept and connection with the game, Utada derived her inspiration from the worlds and characters in Kingdom Hearts and received in-depth explanations and clues from Nomura.

[7] Knowing that the compact discs of the single would be insufficient with the lack of additional material, she decided to create a B-side track that was identical to the first song; this was titled the "After the Battle" version, the composition played during the credits of the game.

[12] Additionally, critics noticed the overlapping technique of Utada's singing, along with the use of reversing certain sections of her voice to hide messages within the song.

[13] "Passion"'s lyrics delve into themes of nostalgia, and discuses the circumstances of past, present and future, which she noted was relatable to the characters in the video game.

[15] Vibe's Mio Yamada said that the lyrics, "expressed weakness and strength simultaneously," and that the material was more mature than Utada's previous work.

[16] Executive producers for Kingdom Hearts and head composer Yoko Shimomura said that the track needed to be more dramatic for the remaining of the accompanying score.

[17] In order to adapt to the remaining material on the soundtrack, Japanese musician Kaoru Wada arranged an orchestral version of "Sanctuary" and was performed by New Japan Philharmonic Orchestra, which included the instrumentation of trumpets, several string sections and percussion.

[21][22] The single was also included on the soundtracks for the "remix" versions of the games, but "Sanctuary" served as its official theme song under her Western name Utada.

[31] In his article for MuuMuse, Bradley Stern said that Utada's vocals and production, "brings the track to another level, transcending the patterns and limitations of most modern pop".

[9] An editor of Square Enix Music rated it nine out of ten points, commending the production and sound; he/she labelled it to be a "masterpiece".

[34] Based on a six-day statistic, the single opened at number four on the weekly chart, selling 49,242 copies, making it her lowest first-week sales at the time.

[36] Because Oricon accumulated two weeks worth of sales due to their New Years policy, the company did not publish an update until January 16, where "Passion" moved two places down with 22,877 copies.

[41] "Passion" debuted at number four on Tokyo Broadcasting System (TBS) Count Down TV chart, a similar opening to Oricon.

and the cathedral (the walls, platform for Utada, floor); Kiriya placed a blue screen behind these structures in order to expand them to higher lengths.

[18] After this scene was complete, Utada wore the same outfit designed by Kozue Hibino, which is a large coated–dress with a trail of puffy inserts, and sung it in the same location.

[18] The ending scene was co-directed by Emmanuel Previnarie, Sze Kwan Chong and Marc Asmode, where she used a flying camera on a small helicopter to accomplish an aerial shot of Utada on the corn field.

[47] The camera then changes positions, aimed towards the singer, and showcases her walking through a large grand hall with purple colored Kachina's in cloaks, hitting drums to the song's beat.

Simon Smith from VGMO.com noted that the visual "involve[d] anime Utada, lots of drum banging, even more horses, and even more dancing kachinas!"

[64] Lil B., an American rapper, released a remix version of his single "Pretty Boy", which sampled the melody of "Sanctuary".

[66] The following year, American rapper French Montana sampled the composition for a song with the same title, which then ended up on his mixtape Mac & Cheese 3 (2012).

[71][72] Subsequently, "Sanctuary" was sampled on AC's song "She Fallin'", from the 2017 album Slappin' in the Trunk Presents: Flight School 2.

[73] According to Bradley Stern, reporting from MuuMuse, he said the recordings were her only entries that gained a global fanbase because of its influence through the video game phenomenon, which was rare of Asian markets to capture outside of their native countries.

[77] A large fan poll on Enix Origin hosted a list that ranked their top 10 Final Fantasy/Kingdom Hearts songs, and "Passion" / "Sanctuary" were placed a number four respectively.

[14] A member at Buzznet listed "Passion" and "Sanctuary" on their top playlist, whilst Joy mentioned the tracks in their "An Intro to Japanese Music in 5 Artists".