Shomin Sample Vol 12

Shomin Sample Vol 12 by Takafumi Nanatsuki. A Comedy manga rated Older Teen, published in English by Seven Seas in 2020.

Ordinary high schooler Kimito Kagurazaka is kidnapped and taken to an elite, isolated girls' academy to serve as a "commoner sample" so the sheltered students can learn about regular people. Pretending to be the perfect commoner is a lot harder than it sounds.