When he was young, Gu Sichen lost his parents and his unborn younger siblings in an accident. This devastating blow left him unable to overcome his emotional trauma, and he developed dissociative identity disorder. Xu Xinxin, a young cleaning lady, accidentally discovered Gu Sichen's secret. To prevent it from being exposed, Gu Sichen hired her under the pretext of making her his "secretary" and kept her by his side. Thus begins their story.