Prism Mates (2011–2011)

In 2011, Mia Kusakabe, Reina Kubo and Karin Takahashi were in a pre-debut trainee group called Prism Mates, where they would participate in the "Pretty Rhythm Studio" live-action segments at the end of each episode in Pretty Rhythm: Aurora Dream. The segments followed them training in dance, singing, and fashion sense for their debut, much like the main characters in the show. The members were all students from Avex Dance Master.

In 2012, Kusakabe, Kubo, and Takahashi debuted under the name Prizmmy, along with a fourth member, Ayami Sema. Sema was the winner of the Pretty Rhythm Award at the Kiratto Entertainment Challenge Contest 2011 Summer, who had also previously worked as an exclusive model for KiraPichi