MADKID is a five-member Japanese dance and vocal unit, making their major debut with the album CIRCUS on April 24, 2019. The members are LIN, YOU-TA, YUKI, SHIN, and KAZUKI. Their fandom name is AXCEL, meaning their fans are the metaphorical pedals that accelerate the group.

They were originally known as J-BOYS-5 with a different lineup of members. The group was formed by KENTO.i, who went on to become a solo act. Member Rikito was also present at the time but has since been replaced by member SHIN, while You-ta replaced KENTO.i. It was around this time that they changed their name to MADKID, representing the desire of youth to defy or rebel against societal norms.

They gained a lot of traction when they released their first anime theme song, “RISE” for the anime adaptation of 盾の勇者の成り上がり (Rising of the Shield Hero), and performed the second opening, titled “FAITH”. Both tracks were written, produced and performed by the group in Japanese and in English and were re-released on their major debut album CIRCUS. Thanks to the anime, they had the chance to perform for the first time overseas and attend their first anime panel at Crunchyroll Expo in San Jose, California in the summer of 2019.

In October 2020, the group announced a reboot, which included several announcements. This included a new album entitled REBOOT, their resigning with record label Nippon Columbia, departure from Slow Jam Productions, signing with their self-run agency Future Notes, a new weekly radio show, a live concert, and the closure of their website and mobile fan club to return to their LINE BLOG.