Koukyuu no Musubibito

Her favorite novel was set in the imperial harem. Now she gets to solve its mysteries! When Xiao Ling took a job at a bookstore, she had no idea she'd be working with her favorite author. Arriving at the palace she'd only read about in stories, Xiao Ling finds not the seasoned authoress she expected, but...the Crown Prince, Ryuhou?!

(Source: MANGA UP!)