Rumi is an insurance agent who is trusted by her clients with her calm smile. However, her main job was MA (mystery agent, undercover investigator) of the National Central Bureau of Investigation, a "masked agent" whose identity must never be known. One day, in the process of investigating "Tokyo Akaoni", which had been marked as a violent organization, suspicious motives were sensed and he was kidnapped. Nyotairyo becomes violent after her body is teased. What will Rumi's fate be...!?