On his 24th birthday, the wealthy heir Jeff has an unforgettable one-night stand with a mysterious woman named Beth. Before he can find her again, Beth reappears—as the newly appointed interim director of his family's company. To his shock, she even claims to be his long-lost elder sister to manage family optics. Forced to interact as both professional colleagues and 'siblings,' Jeff and Beth navigate a minefield of corporate tension and growing attraction. In this game of hidden identities and forbidden sparks, the biggest birthday surprise is yet to come. Can Jeff uncover Beth's real secrets before their feelings cross the line? A sweet and intense story of hidden passion and elite power.