is a Japanese boy band formed under Johnny & Associates (Johnny's) in 2001. The group's name was originally an acronym based on the first letter of each member's family name: Kazuya Kamenashi, Jin Akanishi, Junnosuke Taguchi, Koki Tanaka, Tatsuya Ueda, and Yuichi Nakamaru. Their debut on March 22, 2006, was marked by a tripartite release of a CD single, album and music DVD on their exclusive record label J-One Records. Since then, all of their single, album and music DVD releases have debuted at number one on the Oricon music and DVD charts.
In 2010, Akanishi left the group to start a solo career, making the group's acronym then come from Kamenashi, Taguchi, Tanaka, Ueda, and Nakamaru, and the group toured with five members. In 2013, Tanaka's contract was terminated for several violations, leaving KAT-TUN as a four-man ensemble, and Tatsuya Ueda took the T to keep the acronym. By the end of March 2016, Taguchi left both the group and the agency, leaving KAT-TUN with only three remaining members.
History
2001–2005: Formation and pre-debut activities
Before becoming KAT-TUN, each member belonged to different trainee units within Johnny & Associates. In 2001, eight members were chosen to become a temporary dancing unit in order to support Koichi Domoto in the NHK music program, Pop Jam. The eight members were switched around before it officially became KAT-TUN, with the current three members plus Jin Akanishi, Koki Tanaka and Junnosuke Taguchi. Although the formation was only meant to be a temporary support unit, KAT-TUN gained a great deal of attention and became a solid unit.
In 2002, in response to many requests, KAT-TUN held their first concert called , for which 550,000 people tried to get tickets. That same year, they performed eleven shows in a single day. This is the current record in Japan for the most performances in one day. Since then, KAT-TUN has held concerts in Japan almost every season.
In 2003-2004, their popularity rose to that of a debuted group, to the point where they performed on Music Station multiple times before debuting. In 2005, KAT-TUN released their first major DVD, , which topped the Oricon yearly chart for the best-selling DVD. At the 20th Japan Gold Disc Awards, Live Kaizokuban placed on the Music Video Of The Year list.
2006: Debut and Best of KAT-TUN
On March 22, KAT-TUN released their debut single "Real Face", accompanied by an album, Best of KAT-TUN and a DVD Real Face Film. These were released on their own label J-One Records. The group also went on a nationwide tour, Live of KAT-TUN "Real Face", in support of the album. Within the first week, Best of KAT-TUN, "Real Face" and Real Face Film topped all three Oricon weekly charts by selling 556,548 copies, 754,234 copies and 374,202 copies respectively Total 1,684,984 copies. They became the second artists to do so, the first being Ayumi Hamasaki. With these numbers, KAT-TUN holds the record for the highest weekly single debut sales (previously held by Arashi with their debut single "Arashi" of 557,000 copies sold in 1999). In addition, "Real Face" topped the Oricon charts for three weeks straight, becoming the first debut single to do so in Japan in 8 years 8 months since KinKi Kids' debut single "Garasu no Shōnen." The single sold over a million copies in nine weeks, making "Real Face" the highest selling single for the year 2006.
In March 2006, KAT-TUN became the first group to hold their own performances in Japan's most popular stadium, Tokyo Dome, before debuting. They performed to 110,000 people over two days and about 630,000 people in total during the tour. About three months after releasing "Real Face", KAT-TUN released their second single, "Signal", on July 19.
On October 12, member Akanishi announced a hiatus from the group in order to study linguistics abroad in the United States, leaving KAT-TUN as a five-member group for six months. The remaining members continued activities by releasing their third single, "Bokura no Machi de" as the theme song to members Kamenashi and Tanaka's drama, Tatta Hitotsu no Koi and their second album, Cartoon KAT-TUN II You on December 7.
KAT-TUN is the first group in Japan to have all three singles from debut to exceed 500,000 in yearly sales, taking first, fifth and thirteenth place on the Oricon yearly singles chart.
2007: Cartoon KAT-TUN II You
Under the same name as their second album, KAT-TUN started their second nationwide tour, Tour 2007 Cartoon KAT-TUN II You, still without Akanishi, on April 3. The next day, KAT-TUN began to host their own variety show Cartoon KAT-TUN, which aired every Wednesday from 11:55 p.m. to 12:26 a.m.