Katsuki was eating in the cafeteria with his "friends", Enjiro, Hanta, Mina and other people. As he started to eat...he heard screams...causing a huge commotion behind him...he turned around...really to yell at them...

“WHO THE HECK-"

Katsuki stopped mid-sentence when he saw his younger brother/sister...on the ground...getting hit by a slightly bigger and more powerful guy...Katsuki immediately stood up, he rolled up his sleeves...really to make him suffer for his brother/sister's sake...