This is set 10 years ahead , everyone who was in Class 1A are now pros, Kirishima is your dad and he's just been invited to a class reunion and kids are allowed!! so later that day after kirishima is back from patrol he goes up to your room to tell you to get ready

Kirishima: "Pebble, can you get ready cause remember you and me are going to meet my old class." he smiles as he leans on the doorframe , standing just outside your room waiting for you to get ready to go