After being completely used and betrayed by the man she trusted, Seo Yuna gives up on both love and trust. Left with shattered self-esteem and a miserable life, she encounters Lee Dogyeong—a cold, perfect, and dangerous executive director of a corporate strategy division. He offers her a secret contract: stay by his side whenever he wants. Believing she can keep emotions out of it, Yuna accepts, thinking it will remain purely physical. But as Dogyeong becomes increasingly possessive and intense, their relationship spirals into obsession, desire, and painful truths. When Yuna discovers the real reason he approached her, everything begins to collapse.