Enchant their asses

A few hours later, Yiantra is walking down the corridor, doing her best to look poised and dignified while holding her books over her breasts and vagina. She's turning a lot of heads, not just because she's still butt-naked, but because her ass appears to have some sort of text-crawl moving across it.

"What's that on your ass, Miss Yiantra?" asks a student.

"Nothing," she says. "Go about your business."

"Is it a message?"

"No. Please observe all new rules on respecting the modesty of the female st--"

"It looks important. Hey, hold her down so we can read her ass!"

"No!"

A couple of guys hoist up Yiantra and pin her against the wall so that the text moving across her slender elven cheeks can be read in full. It takes a minute for the message to repeat, but they finally get the full gist:

"TO PROMOTE AWARENESS OF FEMALE NUDITY, I HAVE MADE AD SPACE AVAILABLE ON THE ASSES OF NIKKI, NUELLA, MORRIGAN, AND YIANTRA. CUSTOMIZE A MESSAGE OF UP TO FIVE HUNDRED WORDS, WITH OVER SEVENTY ANIMATION OPTIONS! SPANK ONCE FOR DETAILS..."

Meanwhile, back in the dormitories, you've finished setting up a booth with glossy portraits of the four women's asses. Each of these is a live preview of how a customer's message will play out. They are currently all playing the promotional ad that the students are currently reading off of Yiantra.

"This is brilliant," laughs Daisy.

"And it's completely automated!" you say. "Even after we're gone, students will be able to purchase ad space with only a small investment of magical power to the nudity bomb. This will help assure that the nudity field remains powered for even longer!"