Welcome to the Pleasure Shop

An adult goods store with suspiciously glowing reviews.
Mina, whose sensitivity has been fading, becomes curious after reading the reviews.
By chance, she visits the store and meets the handsome owner, Heetae.
"Then how about trying a demonstration?"
"A demonstration?"
"Yes. We've set up a special dark room just for trials. No one has used it yet,
and I'd love for you to be the first customer. Since it's your first time, it's a free special trial."
Finding herself trying out devices she never expected, Mina begins the experience with a light heart,
only to find herself getting so deeply drawn in that she's reluctant for it to end.
Then, Heetae suggests a 'special' device...