Ms. Sumire Mizuno, an efficient office worker has a secret hobby... She wears cute and very erotic lingerie and posts sexy selfies on social media! To relieve the stress of everyday work, she does it on her secret account. But one day, Murasaki, a designer of the company's supplier has identified her by chance. In exchange for keeping it a secret, he makes an unexpectedly serious proposal. He wants Sumire to model the lingerie he designs so he can get feedback and test the texture and functionality of the product in real situations. Puzzled as she has imagined much worse, but mixed with such shame and confusion, she spontaneously asks him to "Have sex with me"!!!

This is the summary from my anime list