Mei Zhuyu, a calm and reserved nobleman from a lesser branch of the Mei family, arrives in Chang'an as an official at the Bureau of Mystic Investigations. During a banquet, he meets Wu Zhen, the bold and unruly younger sister of the Empress and secret Guardian of the Demon Underworld. Both hide their true identities. Wu, a half-demon striving to keep peace, and Mei, a skilled demon slayer, seek the truth behind the fire 18 years ago. As bone demons rise and unrest grows, they fight side by side, forming a bond that deepens into love until the Changxi Palace launches a purge, forcing them to face each other's secrets and the past they share.

Shi Xiaofan, a modern engineer, transmigrates into a fictional dynasty as Shi Feifan, a notorious playboy, and secretly uses his advanced knowledge to protect his family, build power, and reshape the empire. While pretending to be irresponsible, he quietly amasses wealth, outsmarts political enemies, and rises from “good-for-nothing” to a hidden military force pivotal to the kingdom’s survival.