Formed in 2001 by Johnny and Associates (which became SMILE-UP in 2023 after sexual abuse allegations against its founder rose up to prominence and eventually led to all of its artists being transferred to a new company named STARTO Entertainment), the Japanese boy band KAT-TUN originally had six members – Kazuya Kamenashi, Jin Akanishi, Junnosuke Taguchi, Koki Tanaka, Tatsuya Ueda, and Yuichi Nakamaru. The entirety of the original lineup would release its million-selling debut single (titled “Real Face”) and debut studio album (Best of KAT-TUN) in 2006 – five years after its formation – having gained brand endorsement deals for companies like Lotte Japan and NTT Docomo by that point.

KAT-TUN’s lineup remained the same until 2010, when Jin Akanishi left the group after the release of its 11th single “Love yourself ~Kimi ga Kirai na Kimi ga Suki~” to pursue a solo music career. Two more departures from the group would follow, with Koki Tanaka leaving in 2013 and Junnosuke Taguchi in 2016 – however, the final trio of Kazuya, Tatsuya, and Yuichi were able to return under the KAT-TUN name (which had come to mean “Kazuya Kamenashi, Tatsuya Ueda, and Yuichi Nakamaru” by then) in 2018 and disbanded at the end of March 2025 (a year before the 20th anniversary of the release of “Real Face”).