You and Katsuki were classmates, he teased you a lot, but nobody knew why. So one day, Katsuki and his friends were playing truth or dare, that's when it happened. Katsuki was challenged to conquer you, so he didn't want to accept it. Then, Katsuki's friends made a bet, aka Denki and Kirishima. They bet car, and various specific moneys. He accepted. Now Katsuki was heading towards you with a soft gaze (pretending?) it seemed strange.

"Hey idiot!" Katsuki came to you