Shoko Fujibayashi – lyricist (on 'Wonderful Day').

Chris Gehringer – mastering engineer (on 'Doughnut').

Younghyun – mixing engineer (on 'Doughnut')

KayOne Lee – digital editor (on 'Doughnut').

Dante Kim – assistant recording engineer (on 'Doughnut').

Kate – background vocals (on 'Doughnut').

JuHyeon Jun – strings arranger (on 'Doughnut').

Fingazz – composer, co-producer, all instruments, recording engineer (on 'Doughnut').

Francis – composer, co-producer, all instruments, recording engineer, digital editor (on 'Doughnut').

Rhee 'Rainstone' – composer, producer, all instruments, recording engineer, vocal director, digital editor (on 'Doughnut')

Alexis Kesselman – composer, vocal producer (on 'Doughnut').

Lauren Kaori – lyricist (on 'Doughnut').

To promote 'Doughnut', Twice performed the song on the Japanese television show Music Station. On October 15, 2021, shortly after the release of their first English single, ' The Feels', and the announcement of their third Korean studio album (sixth overall), Formula of Love: O+T=<3, Twice's agency JYP Entertainment announced through a winter-themed teaser that the group will be releasing their ninth Japanese single, 'Doughnut', on December 15.

The single and its B-side, 'Wonderful Day', were physically released on December 15 in Japan. It was pre-released for digital download and streaming on December 3, 2021, by Warner Music Japan as a single from their Japanese full-length album, Celebrate. It is the group's ninth Japanese maxi single, featuring three other tracks. ' Doughnut' is a song recorded by South Korean girl group Twice.

Doughnut country download