Na Haesu spent years sacrificing her own well-being to support her husband, Kang Mincheol, working multiple jobs to pay off his massive debts. Despite their beautiful beginnings as "unfortunate youths" who relied on each other for survival, the marriage turned toxic after a tragic miscarriage. Mincheol, unable to handle his perceived failures as a provider, began to resent and gaslight Haesu, eventually having a blatant affair with a younger coworker, Do Hee-ji. As Haesu’s life crumbles, she encounters Beom Taeha, a mysterious younger man who has been quietly watching her. Taeha is wealthy, intense, and seemingly inexperienced in love, asking Haesu to "teach" him about it. While he provides her with a sense of safety and affection she hasn't felt in years, his devotion is often described as borderline obsessive and manipulative.