Her Royal Highness, Unattainable

Poisoned to end the royal line, Crown Prince Su Jin must rule as a man. Her clashes with Regent Xiao Heng turn to forbidden passion after a plotted encounter. When he discovers she's a woman while saving her from assassination, protector becomes partner. Together they crush a rebellion, and she unveils her father's secret decree to become the first female emperor—ruling alone for 38 years with him as her silent shadow until death reunites them forever.