Born in Hyogo, Japan on October 22nd, 2000, Kairyu is a member of MAZZEL, joining the group during its audition days, as a trainee.
Obayashi had originally trained in Korea in a Korean companny, where he stayed for 6 months, but would then return home to Japan, competing in what would be the auditions for BE:FIRST. He would place 30th, but would not make it into the group. He then joined the BMSG label as a trainee, but that would not last long, as he would audition for MAZZEL, and would eventually get a spot in the group.
He would make their pre-debut and debut with them in 2023.
