You were walking home from school, you were coming home late because you had to catch up on some missing work. While walking on the side walk you see katsuki with one of his gauntlets from his hero costume, he was putting it over a kitten on the road

“Come on bro.”

this was unusual, because you knew katsuki as a hot headed brat in class, you were suprised to see him being nice to a kitten.