User blog comment:Daniel132777/Who is the Real Invisible Boy?/@comment-28171460-20160704010606

I think that you are probably right, the invisible boy is most likely Max. However, Max is never directly adressed as "the invisible boy." In My Best Friend is Invisible, Brent is called that.

Direct quote from My Best Friend is Invisible: "Brent Green. An invisible boy. Right in my room."