Story of Saiunkoku (2006)

Born into a noble but impoverished family, Shuurei agrees to play the role of concubine to the new emperor, Shi Ryuuki, in order to teach the reckless leader -- who's rumored to exhibit an appetite for bedding noblemen -- how to rule. The promise of riches for her family and the opportunity to live at court keep her motivated to continue the job despite the many challenges the emperor throws her way in this visually appealing anime series.