The Princess's Shadow Guard

I transmigrated into a princess overnight. This identity is amazing! My mother is a sweet, silly type, and has been my father's favorite in the harem for years. My father is bold and domineering, but really, he's a total wife-lover. There are so many concubines in the harem, each lonelier than the last. I have just one older brother, and he spends all day fighting me for food. As expected of my real brother. The beloved eldest princess, Xiang Xiuying, keeps gaining more people to rely on. Life is fantastic, except for that man who appears and disappears without a trace. He's so annoying! He's followed me everywhere since I was little, even when I'm taking a bath! #Sweet romance, doting love, and Mary Sue vibes! The only word for it is satisfying!# Notes: 1. The princess may be a goofball, but she's not someone to mess with. 2. The shadow guard is a lovesick stalker. Don't expect him to accomplish anything great. 3. This is a Mary Sue story! A Mary Sue story! A Mary Sue story! Important things must be said three times! 4. Set in a fictional world. The author has never written an ancient romance before, so I'll write however I want. No research or nitpicking, please.