Reading through Hiroyu's old blog, him and Mirai were friends through a brand (he says a worker and customer relation?), but he met Hiromu through a band recruitment bulletin board. Apparently there was a bass player before who left due to family issues, but there was no name or date anything in the post. Maybe it was before the band was official because he said also he wanted to be in a band as a hobby? It's an interesting thing to note either way