Track M1-10 Passion served as the theme song for Kingdom Hearts II.

All songs written and composed by Hikaru Utada, except "Hymne à L'amour ~Ai no Ansemu~" lyrics by Édith Piaf and music by Marguerite Monnot, with Japanese translation by Utada.

Managerial

Miyake Akira – producer
Yuuko Honda – musician coordination
San-e Ichii – executive producer
Michael T. Martin – overseas production contractor
Fumio Miyata – musician coordination
Hidenobu Okita – director
Hikaru Utada – producer
Teruzane "Skigg" Utada – producer
Norio Yamamoto – Los Angeles session coordination
Performance credits

David Carpenter – bass (M1-9)
Chris Chaney – bass (M2-2)
Yamaya Honda – drums (M2-4)
Takashi Itani – percussions (M2-4)
Noriyasu Kawamura – drums (M2-1)
Kinbara Chieko Strings – String section (M1-6)
Tsuyoshi Kon – acoustic guitar (M1-6, M1-11—1-12, M2-1)
Makiyama Junko Strings – String section (M1-1)
Ben Mauro – guitar (M1-10)
Russel McNamara – guitars (M1-13)
Gary Novak – drums (M2-2)
Akemi Ohta – flute (M2-4)
Hiroshi Okamoto – acoustic piano (M1-6, M2-1, #205)
Dan Reynolds – drums (M1-13)
Forrest Robinson – drums (M1-10—1-11)
Matt Rohde – acoustic piano (M1-10, M2-2), keyboards (M1-9—1-10, M2-2)
Alexis Smith – electric bass (M1-6), keyboards (M1-6)
Masato Suzuki – bass (M2-4)
Synergy Vocals – chorus vocals (M2-3)
Takeshi Taneda – bass (M2-1)
Yuzuru Tomita – acoustic piano (M1-2), keyboards (M1-7)
Masayasu Tzboguchi – electric piano (M2-4)
Hikaru Utada – acoustic piano (M1-2, M1-12), keyboards (M1-1—1-5, M1-9—1-12, M2-2—2-3, M2-5), vocals
Phil Xenidis – guitar (M2-2)
Visuals and imagery

Asuka Katagiri – photo
Manabu Mizuno – art direction
Masaru Uemura – design
Kazuhisa Yoshimoto – retouching
Technical and production

Matsui Atsushi – mixing (M1-7), recording
Daniel Burns – recording (M1-9, M2-2)
Glenn Erwin – Pro Tools operation (M1-10)
Goetz B. – mixing (M1-1—1-11, M2-1-2-2, M2-4—2-5), recording (M2-3)
Goh Hotoda – mixing (M1-12), recording (M1-12)
Ted Jensen – mastering
Naruyoshi Kikuchi – arrangement (M2-4)
Masahito Komori – recording (M2-3)
Damien Lewis – additional/assistant engineering (M2-3)
Russel McNamara – production, programming (M1-13)
Matt Rohde – arrangement (M2-2), programming (M1-9—1-10, M2-2)
Alexis Smith – additional programming (M1-5, M1-8—1-10, M2-3, M2-5), arrangement (M1-6), programming (M1-6)
Masaki Takamura – recording (M2-4)
Brian Taliaferro – additional programming (M1-11)
Phil Tan – mixing (M2-3)
Yuzuru Tomita – additional programming (M1-1—1-5, M1-8, M2-3), arrangement (M1-6—1-7), programming (M1-7), string arrangement (M1-1, M1-6)
Kazuhide Tsunemi – additional programming (M1-1)
Hikaru Utada – additional programming (M1-7), arrangement, programming (M1-1—1-5, M1-12, M2-2, M2-5), string arrangement (M1-1, M1-6)
Pat Woodward – recording (M1-10)
Takuo Yamamoto – string arrangement (M1-6)