Answer by taking a quote from the following article:

Ai Carina Uemura (Zhi Cun  Ai  karina, Uemura Ai Karina, born November 2, 1981), known mononymously as Ai (Japanese pronunciation: [ai], stylized as AI or A.I. ) is a Japanese-American singer and songwriter who was born in Los Angeles. Ai spent her childhood in both Kagoshima, Japan and Los Angeles. She debuted as a singer in 2000, later moving to Def Jam Japan and rising to fame with her album 2004 Ai.

As is standard for Japanese musicians, Ai has featured as a spokesperson, or has her music featured, for many products. Ai's songs have been used as TV commercial songs, drama theme songs, film theme songs and TV show ending theme songs.  Ai has worked on four major Coca-Cola TV commercial campaigns, two featuring her own songs ("You Are My Star" (2009), "Happiness" (2011)) and two featuring collaborations (K'naan's "Wavin' Flag" (2009), Namie Amuro's "Wonder Woman" (2011)). She has also been featured in two Audio-Technica campaigns (using "My Friend (Live Version)" and "I'll Remember You", a campaign for Japan Airlines ("Brand New Day") and Pepsi Nex with "I Wanna Know."  Ai's most high-profile work for a TV drama was the theme song for 2006's primetime drama Team Medical Dragon, "Believe", which was one of her greatest hits, selling over one million ringtones. Ai also sung the theme song for the drama's second series, "One." Ai also worked on the theme song for the 2010 primetime drama Keishicho Keizoku Sosahan, "Nemurenai Machi." Other program theme songs include the Japanese theme song for the American drama Heroes ("Taisetsu na Mono"), and the 15th ending theme for the children's animation Crayon Shin-chan, "Crayon Beats"). In 2005, Ai's song "Alive (English Version)" was used as an insert song for the South Korean drama Delightful Girl Choon-Hyang.  Many of Ai's songs have been used in films. Her "Story" song was remade (also with its English version) for Disney`s box office Big Hero 6 in 2014. She performed the theme song for Departures (2008), the winner of the Academy Award for Best Foreign Language Film in 2009. She has also sung the theme songs for Crayon Shin-chan: The Legend Called Buri Buri 3 Minutes Charge (2005), Pray (2005), Lalapipo (2009) and Berserk Golden Age Arc I: The Egg of the High King (2012). Her music has been featured on the soundtracks of TKO Hiphop (2005), the musical film Memories of Matsuko (2006), in which Ai cameoed to perform the song, and Heat Island (2007).

What other movies?
She performed the theme song for Departures (2008), the winner of the Academy Award for Best Foreign Language Film in 2009.