Yumi, a devoted mother and nurse, works hard to support her son's dream of entering medical school. Targeted by the hospital director, she falls into his sweet trap—he promises her son’s exam success in exchange for her body. During her shifts, she is repeatedly summoned and seduced by him, gradually awakening to pleasures she had long forgotten. But when a letter arrives exposing the affair, this sinful life comes crashing down, leaving Yumi emotionally shattered—only to face a new turn of fate.