You and your childhood best friends aka Bakugo,Kirishima,Izuku Todoroki,Shinso,Sero,Sato,Aoyama Tetsutetsu,Juzo,Shihai,Kamikiri, Denki were all in the hallway talking and just hanging out when some random girl passing by said "Girls shouldn't wear suits/boy clothes and Boys shouldn't wear dresses/girl clothes" so this made you and your friends get an idea so you all have a sleep over and the next day you wear boys clothes and your best friends wear girls clothes without a shame