* In a KAT-TUN spring concert on 3 April 2007, 5 members of Johnny's Jr's were named to be part of a new group called Hey! Say! 7. These members were Yuya Takaki, Daiki Arioka, Yuto Nakajima, Yuuri Chinen and Ryosuke Yamada. Initially, the temporary status of the group was unclear, worrying a lot of fans of Johnny Jr's groups J.J. Express as it could mean that the group was splitting up and that Yuya Takaki and Daiki Arioka would permanently be in this group instead.
* On 16 June 2007, it was announced that Hey! Say! 7 would release a single, Hey! Say!, which was then used as the opening song for the popular anime Love★Com (Lovely Complex). The single also contains the ending song used for the same anime, titled BON BON. This is the first time a Johnny's Jrs group released a single since Ya-Ya-yah in 2002, and there was uncertainty in whether if the debut is permanent or just a CD release.
* On 1 August 2007, the single Hey! Say! was released. The following week, on 8 August 2007, Oricon Style confirmed that Hey! Say! sold 120,520 copies in its first week and this made it top the Oricon Weekly Charts. At the same time, Hey! Say! 7 broke an all-time record by being the youngest group to ever reach the number 1 spot in the Oricon chart, with their average age being just 14.8 years.
* In the month of August, the single Hey! Say! topped the Oricon Monthly Charts, outselling even their Johnny's Entertainment seniors, Tackey and Tsubasa and TOKIO. Since then, the Hey! Say! single had been certified gold by the RIAJ.
Transition to Hey! Say! JUMP
* On 24 September 2007, in a live television event from the Johnny's Jr's concert in Yokohama Arena, it was announced that the group would debut under a new name. Hey! Say! JUMP consists of all 5 members of Hey! Say! 7, now split into two subgroups and are joined by 5 other Johnny's Jr's. It has also been announced that they will debut their single on 14 November 2007, titled Ultra Music Power, and the song will also be used as Japan's World Cup Volleyball Relay 2007 Theme Song.
Former Hey! Say! 7 (Temporary Group)
The former Hey! Say! 7 (temporary group) which existed from 3 April 2007 - 23 September 2007 consists of 5 members. This group no longer exists, although the name had been recycled to be used as a new subgroup under Hey! Say! JUMP. The members of this group have been split up into the two new subgroups.
* Yuya Takaki / 高木雄也 - March 26, 1990 (1990-03-26) (age 20)
* Daiki Arioka / 有岡大貴 - April 15, 1991 (1991-04-15) (age 19)
* Ryosuke Yamada / 山田涼介 - May 9, 1993 (1993-05-09) (age 17)
* Yuto Nakajima / 中島裕翔 - August 10, 1993 (1993-08-10) (age 16)
* Yuuri Chinen / 知念侑李 - November 30, 1993 (1993-11-30) (age 16)