PROTOSTARProtostar is the debut single of JO1. JO1 is a Japanese boy band formed through the reality competition show Produce 101 Japan. The group is composed of eleven members: Issei Mamehara, Ren Kawashiri, Takumi Kawanishi, Shosei Ohira, Shion Tsurubo, Ruki Shiroiwa, Keigo Sato, Syoya Kimata, Junki Kono, Sukai Kinjo, and Sho Yonashiro. JO1 is the first Produce 101 winning group that is intended to be permanent. It is managed by Lapone Entertainment, a joint venture between Yoshimoto Kogyo and CJ ENM.