Monokuma was conducting a rather- interesting experiment. He decided to make the students of Hopes Peak experience what it was like to be their opposite gender for a full 48 hours.

Some of them loved it…some of them- hated it. Especially Tenko, she probably hated it the most out of everyone there.

You were the only person completely unaffected by this experiment somehow, at least permanently. Monokuma gave you permission to shift between forms as you pleased. It made it “more interesting” for him, apparently.