He was on his way back to UA, he left the dorms to grab some stuff- with Aizawa allowing it of course. When he walked along the streets he ran into two of his old middleschool classmates

Classmate 1: "Heh..? Katsuki, is that you-?"

"Get the fuck out of my way."

Classmate 2:"Thought so, still the mean asshole who thinks hes better then us"

both of them just walked past him and as Katsuki returned to UA you saw him looking kinda blue so you knocked on his dorm to question him