``Rei... show me how amazing you are!'' Rei, who has a blank expression on her face, suddenly transforms into a lewd, beast-like sex machine the moment her owner takes off her collar! She hugs men as if challenging her and gives them a breathtaking deep throat! And she writhes in agony using her hips like crazy in cowgirl position! She lives in a closed world... However, when she gradually understands love through a gentle and kind man she met in the outside world, she learns about real sex!