Rebecca slowly started to lift her skirt up, hoping against all odds that the teacher would assure her it was just a joke and start class. Only that didn't happen, and she was standing in front of her teacher, parading her black panties.
"Turn around, please," she said, after inspecting them for a while.
"No!" she said, finally finding the courage to stand up for herself. "My undies aren't for show, miss," she said in a mocking tone, as she let go of the hem of her skirt.
"Well, miss," she said, her voice suddenly a lot colder, "I don't know about your previous school, but here, disobeying teachers is the sort of thing we don't tolerate. Miss Tomsky," she called, to which a slim, blonde girl stood up from the third row. "Please come over here and remove your skirt."
The girl muttered a "Yes, Ms Main", and did as she was told, handing the skirt to the teacher apparently named Ms Main.
"Good girl. Now lift your blouse up a bit, so we can all look at your underwear."
She did so, completely exposing her white panties to around a dozen girls and just as many boys.
"Thank you. You may get dressed. See? It isn't so hard. You will be just as well behaved in no time, don't worry. I know that, because student here who are not well behaved get punished. Just like you will be, for disobeying me. Now, be a good lass, and lift your skirt up."
She reluctantly did so, her face going red as she exposed herself to the entire class. Ms Main let her stew for a few moments, before speaking to the class.
"Now, does anyone think that these look like uniform clothes."
She welcomed the silence. It meant that at least the class had empathy for her. Except...
"No, Ms," said the blonde girl from before, Tomsky. "All our regulation underwear is white. I can also see her through her top that her bra is black."
"Very well. Thank you, Miss Tomsky. Now, Miss..."
"White," Rebecca said.
"Miss White, as you probably guessed, wearing non-uniform clothing is also against our school's rules, so I will have to confiscate those. You may lower your skirt, and hand them to me."
"What? You can't make me wear a skirt and no panties! And this blouse is so thin, I don't want my tits poking through!"
"First of all, I am not making you wear anything. Our clothing regulations aren't prescriptive. You do not have to wear any part of our uniform, you simply cannot wear anything else. So, you will hand your bra and panties to me. During your break, you're free to put on the ones that came with your uniform. Second of all, your refusal to simply do as I say has earned you additional punishment, and just now I heard some very coarse language from you, which is also forbidden. So I suggest you refrain from talking in the future."
Beaten, Rebecca had no choice but to surrender. She crouched down, carefully slipping out of her panties without giving anyone a free show of her privates,and then she reached under her blouse and undid her bra. She was blushing before, but now her face was red as a lobster. She felt vulnerable, she felt like every one of her classmates was sizing her up. What if her skirt hikes up as she sits down? Or she gets cold and her nipples poke through her shirt?
Of course, these worries were very mild, compared to what awaited her...