Wear the White Mage robe.
From Create Your Own Story
The white mage is one of your favorite Final Fantasy characters to cosplay, mainly because the costume is simple and easy to assemble. You slip into the white tunic with the red embroidery and fastened the brown leather belt. You noticed that since this is an old outfit, the tunic that was supposed to extend down to your knees now only covers the upper part of your thigh, leaving a large portion of bare flesh exposed. Even more, when you sat down on your bed and raised your leg to put on the knee-high leather boots, you can see in the mirror that your white cotton panties are also visible from a certain angle. You stood up with the boots on and quickly tugged down at the skirt of the tunic to cover more skin.
At least the upper part will be covered up, you thought to yourself as you tightened the ribbon at the collar. And once you put on the white mage cloak, the length of the cloak will cover up any portion of bare legs from prying eyes of potential pervs at the party.
After you donned the long white cloak with its white hood, you inspected yourself in the mirror. Not too bad.
