The name refers to the Heisei period during which all members were born, as well as to the year 2007 as the group's formation year. Ap( April 3, 2007) – Septem( September 24, 2007)ĭuring a KAT-TUN spring concert on April 3, 2007, Yuya Takaki, Daiki Arioka, Ryosuke Yamada, Yuto Nakajima and Yuri Chinen were announced to become part of a temporary group called Hey! Say! 7.
