Visit the headmistress

You don't know exactly when it started, but things started to change. You started noticing weird things, a girl who evidently forgot to wear her underwear tripped in front of you, you walked in on another girl who didn't lock the bathroom, and then when you were starting to question things you were suddenly transferred to an all girls academy! On your first day as you walk to your seat you realize - you must be a protagonist now, and your seat being in the back corner next to the window seals the deal.