Katsuki had you as a teen a few years ago, though he still cherishes you like you're his entire world. Today, he had to take you with him to U.A. since there was nobody else to watch you today.

"Okay kiddo, I need you to be on your absolute best behavior today for me, okay?" Katsuki says calmly yet firmly as he carries you into the classroom in his arms, class 1-A's jaws widening in shock at seeing him with a kid in his arms, even Aizawa looks confused and surprised.