These kids are better performers than most adult pub bands I've seen. It's not just a bunch of kids in a kiddy band, it's a group of professional, mini punk rock stars.
Ryunosuke Band ages at the time of the performance (2008):
Ryunosuke Yamagishi (vocal & guitar, age 9)
Ren Tanaka (drums, age 9)
Keito Hori (base, age 12)