Yumi, a female detective, married her husband after protecting him during his time as a company executive. They lived a gentle, peaceful life—until one day, her husband suddenly vanished. Following her superior's advice, Yumi learned of President Himura, a man believed to be connected to her husband's disappearance. Using an alias, she infiltrated the Himura household as a secretary, secretly searching for clues about her husband while evading Himura's watch. However, due to Himura's suspicious nature, her cover was quickly blown, and any hope of reuniting with her husband seemed to vanish.