His childhood friends and former classmates include fellow The Rampage member Rui Yonamine, JO1's Sho Yonashiro and model Ryucheru/Ryuchell.
[2] Kamiya has been active as a child actor and starred in the two films Ryukyu Cowboy Yoroshiku Gozaimasu (2007)[3] and Nirai no Oka〜A Song of Gondola〜 (2010).
During The Rampage's musha shugyō, he did indeed sing on stage two times, however his official position in the group is only being a performer.
In this sub-unit he takes on the position of a vocalist, marking the first time he would provide his vocals to any work of The Rampage.
The quintet made their official debut as MA55IVE THE RAMPAGE with the digital song "Determined" on February 6, 2020.