@Punllarena
Or they did read that (or at least understand it's the character and not the cosplayer) and are just trolling. It's the internet, after all.
@Leigh86
What if he was just showing his school ID to get something like a student discount? At which point the clerk was surprised he was in high school and not much younger. The bigger concern is how he didn't notice she was wearing the uniform from his school. But I'll forgive that detail...