Ai Kuwabara (桑原あい) was born on September 21, 1991 in Chiba Prefecture. As a child she played the electone, Yamaha's electronic organ, and won gold prizes at the All Japan Yamaha Electone Contest; in 2004 the magazine AERA featured her as a young electone prodigy. She turned to the piano in the second half of junior high school and studied as a jazz piano major in the music department of Senzoku Gakuen High School. After graduating she gave her first live performance in April 2010, a show she produced, directed and composed herself.

Her first working band was the Ai Kuwabara Trio Project, with the bassist Yusuke Morita. The trio's debut, From Here to There, reached Japanese stores nationally through EWE Records in November 2012, and the second album, The Sixth Sense (April 2013), made her name: it reached No. 1 on the Tower Records jazz chart, was named best album of the first half of 2013 by The Japan Times, and won the New Star Prize at the 2013 Nissan Presents Jazz Japan Awards. That year she played the Sapporo City Jazz Festival, took the trio on its first American tour (Berkeley, Los Angeles, Denver and Anchorage) and appeared on the main stage of the 12th Tokyo Jazz Festival in September. The Window, recorded at Onkio Haus in Tokyo on December 19 to 21, 2013 and released in April 2014, added the drummer Shun Ishiwaka alongside the drummer Shintaro Imamura.

Solo piano competitions followed. She won first prize at the Montreux Jazz Solo Piano Competition held in Kawasaki in 2014 and was a finalist in the Parmigiani Montreux Jazz Festival Solo Piano Competition in Switzerland in 2015, where she met Quincy Jones. Her official biography says Quincy Jones Productions then presented her in Los Angeles and New York in 2016 and 2017. The trio's fourth album, Love Theme (April 2015), was recorded at Onkio Haus on December 27 to 29, 2014 with Morita on electric bass, Takashi Sugawa on contrabass and Ishiwaka on drums, and its programme runs from Ennio Morricone's Once Upon a Time in America theme and the Beatles' "Here, There and Everywhere" to King Crimson's "21st Century Schizoid Man."

In October 2016 she recorded in New York with the drummer Steve Gadd and the bassist Will Lee, both veterans of New York studio and touring work. Somehow, Someday, Somewhere was made at Sear Sound with the engineer Jay Messina, produced by Kiyoshi Itoh, and released by T.O.M. Records on February 8, 2017. Quincy Jones is quoted on her official site as saying, "Ai's heart leads her to greatness and it's beautiful to hear and see." The three of them also played together on stage: Live at Blue Note Tokyo, recorded at the Tokyo club on September 23, 2018 and released by Verve on March 20, 2019, is counted as her eighth album.

Her major-label home became Verve. Dear Family (November 8, 2017), a piano and drums album with Ishiwaka, doubled as a television theme: its opening track served as the opening music of TV Asahi's weekend programmes Saturday Station and Sunday Station, for which she was the credited composer from April 2017 to September 2020. To The End Of This World (August 22, 2018) introduced a new trio billed as Ai Kuwabara The Project, with the bassist Keisuke Torigoe and the drummer Muneomi Senju, and featured the tenor saxophonist Ben Wendel on "The Error," the rapper Daichi Yamamoto on "MAMA," and a string quartet and vocalist Sara Yoshida on other tracks. My First Disney Jazz (Walt Disney Records, August 28, 2019) arranged songs from Aladdin to The Nightmare Before Christmas. In October 2019 she played piano on two tracks of Blue Note Voyage, the Blue Note 80th anniversary session billed under Takuya Kuroda's name first, taking "Maiden Voyage" with Kuroda and Ishiwaka and arranging Bud Powell's "Cleopatra's Dream" herself.

The solo piano album Opera (April 7, 2021) is a set of eleven pieces in which several of the songs were chosen by guests, among them Kavka Shishido and Ikusaburo Yamazaki; it ranges from Ennio Morricone's Nuovo Cinema Paradiso theme and Bill Evans's "Waltz for Debby" to Bon Jovi's "Livin' on a Prayer." Making Us Alive, released on September 28, 2022 to mark the tenth anniversary of her debut, is a live trio record with Torigoe and Senju assembled from concerts at Billboard Live Osaka, Blue Note Tokyo and Ajioka Civic Center in Aichi in June and July 2022, with Duke Ellington's "Money Jungle," the Talking Heads' "Psycho Killer" and Joni Mitchell's "Both Sides Now."

A good part of her working life is composing and directing for the stage and screen. She composed and directed the music for the musical In a World of Never Ending Rain (2022), served as music director and keyboard conductor for the Japan premiere of War Paint in 2023, for Anzu: Opening the Door to the Heart in August 2025, and as composer and music director for the Japanese production of The Intouchables (Saikyo-no-futari) in May 2026. She also composed theme music for J-WAVE and for the Isetan department stores, and played piano on the second Mobile Suit Gundam Thunderbolt soundtrack with Naruyoshi Kikuchi and on the Splatoon 2 soundtrack.

In 2024 she moved her base to Los Angeles and now divides her time between Los Angeles and Tokyo. Flying? (Verve, July 9, 2025) came out of sessions with Los Angeles musicians, built around a trio with the bassist Sam Wilkes and the drummer Gene Coye and including an original, "What Hummingbirds Teach Us About Flying," alongside covers of Maroon 5's "This Love," the Red Hot Chili Peppers' "Parallel Universe" and Michael Jackson's "Heal the World." She turned 35 in September 2026.

Kuwabara writes and plays as a trio leader in the contemporary mainstream of Japanese piano jazz, with a taste for rock and pop material reworked as jazz. The Sixth Sense was inspired by her interest in psychology and cognitive science, and its track titles ("Intuition," "Brainwork," "Laboratory") follow that theme. The critic Sean Smith heard The Sixth Sense as contemporary jazz blended with rock and fusion, with some prog-rock-like synthesizer sounds. Her own repertoire bears that out: King Crimson, the Talking Heads, the Velvet Underground's "Pale Blue Eyes," the Rolling Stones' "She's a Rainbow," Massive Attack and Maroon 5 sit on her records next to Ellington's "Money Jungle," Evans's "Waltz for Debby," Astor Piazzolla and Egberto Gismonti.

She is also an unusually active composer for theatre, television and radio, and her Disney and pop-cover records reach beyond the usual jazz audience. The jazz identity is nonetheless clear: Discogs tags her leader albums Jazz, nearly all with the style Contemporary Jazz, her label is Verve, and the recognition she has received, from the Jazz Japan Award and the Tower Records jazz chart to the Montreux piano competition and the Tokyo Jazz Festival, comes from the jazz world.