She decides to put on the underwear, right there, in the middle of the store.

"I need to feel it", Said Marie, upon which, she grabbed the pair with her hands. Seeing such cute and elaborate pair of underwear, made Marie ansious to try it out for herself, and so, to that end, she began to undress, removing her shirt and skirt right there in the middle of the store to do it.

Due to her unfamiliarity with human norms and customs, Marie didn't knew that you were supposed to try out clothing in the chaging booth, or that undressing in public was improper, for her, she was just trying out some clothing, and there was nothing else about it. Thus even, as she got half-naked in the middle of the store, with everyone seeing her, she didn't comprehend that what was she doing was wrong or obsene.

"MARIE!!, what are you doing ?!", exclamed Yukiko surprised at the boldness of her act.

"I'm just trying out this pair of underwear, that's all", Marie responded as she proceeded to unclap the straps of her bra.

"But you can do that in the changing booth", Yukiko replied, as she tried to stop her from stripping in public.

"Changing...Booth...?", Marie replied as she didn't knew what was that.

"Oh, i get it, it was full isn't ?", Yukiko asked.

"Yes...?", Marie responded as she put her thumbs in her panties.

"Ok look, don't worry, i-i can help you", said Yukiko nervously as she went for a towel to help Marie change in privacy. Making Marie confused as to why would that be important.