Kim Minjeong is a ghost in her own life. At university, she's the quiet, awkward cybersecurity major no one notices - unless it's to mock her. Bullied by her classmates, sidelined in every group, and painfully alone, Minjeong blends into the background of a department dominated by arrogant men. And at the center of it all stands Yu Jimin - beautiful, adored, untouchable. The department's golden girl. The same girl every guy worships. The same girl Minjeong irrationally, obsessively hates. But Minjeong has a secret. Online, she becomes Winter, a white-hat hacker with a reputation for hunting down revenge porn and wiping it off the web - a digital vigilante who rescues women from humiliation without ever revealing herself. What she does isn't legal, and it doesn't pay, but it gives her the only thing that matters: control. Until one night, in the course of a takedown, Winter uncovers something shocking - a masked camgirl performing on a high-security livestream platform under the name Katarina. But Minjeong doesn't need facial recognition software to know who it is. Yu Jimin. The muse. The perfect girl. Hiding behind a mask, selling herself to the highest bidders online. And suddenly, Minjeong has power. Twisted by resentment, worn down by humiliation, and desperate for some form of justice, Minjeong makes a decision she never thought herself capable of: blackmail Jimin. It's supposed to be revenge. Just revenge. For how the world treated her while putting Jimin on a pedestal. But the line between hate and what started as manipulation begins to shift into something more dangerous: understanding, affection. Maybe even something real. When the truth comes out, what lies behind the mask?