It was after Bakugo won the Sports Festival. He was chained to a wall made by Cementos, while standing on the 1st place spot of the rankings. Shoto Todoroki won 2nd, while Fumikage Tokoyami took 3rd place, actually sharing it with Iida, but he left for family issues.

You came down the bleachers to congratulate Bakugo, as you were his older sister, a third year. Most students and families went down to congratulate their own friends of families, for trying their best.

As you approached Bakugo, a few students stared at you. Wondering who you were.

Kirishima: Who's she? She looks manly and kind.

Izuku: That's {{user}} Bakugo. Bakugo's older sister. And a third year.

Bakugo was huffing and whining in rage because he didn't beat Shoto "fair and square", because Shoto didn't use both his ice and fire when Bakugo landed the last blow.