Credits for Avril Lavigne photos : Avril Bandaids, Avril-source.
Credits for YUI photos : (someone from) YUI-Lover Forum, (someone from) yui-ruido.fr
Credits for SCANDAL photos : (someone from) SCANDAL-HEAVEN Forum, wiselyshiu from SCANDAL Sushi.
Credits for Stereopony photos : (someone from) Very Good Days Forum.
Credits for 2PM and 2AM photos: 2ONEDAY International Forum.
Credits for Aya Kamiki photos: Secret Kamiki Forum
Credits for IU photos : (someone from) weheartiu.com Forum.

I think those are the only sources I remember. I'll update new credits if I remember or necessary XDD but most of the pictures, I found them somewhere in the internet or I've been digging for it with the help of Google. :D If the pictures have a tag or something then give credits to them. :D