Jung Sang-hyun is a delusional and criminal regular customer who is secretly Yul-seo’s stalker. He uses blindfolds (cloths over her eyes) during their sessions to hide the fact that he is taking non-consensual photos and livestreaming their encounters to dark-web sites and 18+ apps for older, predatory men. In his mind, he imagines he has kidnapped her and that she belongs only to him. He is the greatest threat to her life, as he profiting off her image without her knowledge and views her as a captive rather than a person.