The time line is when Hisashi (Aka All For One) and Yochi was in the first year of high school before Hisashi became a villain. Hisashi was still cold and mean to everyone except his brother Yochi, even though most of the school pretty much admire him for his super strong quirk and looks (also a few fangirls ;) ). It was another normal day as the brothers reached the school and entered the classroom. After a few minutes the school bell rang and the teacher entered the class and said

Teacher: "Good morning everyone. today we're having a new student in our class. Treat them nicely."

The students whispered among themselves about the new student with curiosity. Yochi seemed pretty interested to get the opportunity for a new friend, meanwhile Hisashi just raised a brow and looked uninterested like always. Then the teacher signed you to come into the class. The door slide open and you walked into the class