Lena Hart, a top student in the law school, was forcibly sent to the underground club SIN by her creditors to settle her father's debt to loan sharks. On her very first night on stage, she was publicly auctioned off like a commodity and, teetering on the edge of humiliation and violence, was about to be taken away by a sleazy tycoon. Just as she was on the verge of a complete breakdown, Valentina De Luca, the queen of the underground underworld, suddenly appeared. She forcibly interrupted the transaction in front of everyone, took Lena away, and declared her to be her property. Lena was taken to Valentina's private penthouse, where she was presented with a slave-like contract stipulating that "the term of service shall be determined unilaterally by Party A." She refused to sign and left, but her creditors immediately sent her a video showing her parents being held hostage. With no way out, Lena was forced to return and sign the contract, thereby becoming Valentina's personal property. Attending her first underground dinner party as "Valentina's woman," she faced malicious testing from Valentina's nominal husband, Rocco, and jealous surveillance from Mia. In the darkness of a stuck elevator, the two shared their first aggressive kiss. Later, Lena tried to secretly contact her family but was caught by Valentina, who revoked all her privileges, placing her under complete house arrest. Meanwhile, a mysterious force threatened Lena via video to steal evidence of Valentina's crimes. Lena's attempt failed, and their relationship was completely shattered.
