Hey.. So uh.. This isn't a foreword but I wanna say that, here in Singapore, we have elementary school till you're 12 and you have middle school which I guess is secondary school till you're 16/17. And from there you go to University. So that's why Jun and Yoona are in the same school although Yoona was 15 and Jun was 17. So yeah. And.. In this story, BEAST was formed a long time ago and only 5 members were in the group until Jun joined.