Demona collossa's manga / #student(1)

http://www.mangago.me/read-manga/boku_kara_kimi_ga_kienai/mh/v03/c014/33/ Who are these guys? I know they are from a manga I've read, but I can't remember the name, seriously it's litteraly killing me here Btw, I mean those guys in flashy clothes who looks like their in a rock band, because I think I linked the wrong picture he he...