KAT-TUN are a Japanese pop/rock quartet formed under Johnny & Associates (JE) in 2001 in Tokyo, Japan and signed to J-One Records, their own exclusive record label under J Storm, Inc., in 2006. The group consists of Kazuya Kamenashi (亀梨和也), Junnosuke Taguchi (田口淳之介), Tatsuya Ueda (上田竜也) and Yuichi Nakamaru (中丸雄一). Their name is derived from the first letter of the members' family surnames. The pronunciation is supposedly close to the English word "cartoon" (or kah-toon). Former member Jin Akanishi (赤西仁) left KAT-TUN in 2010. Koki Tanaka (田中聖) left KAT-TUN in 2013.