Transmigrating into Qian Qiuyue, the notorious Black Mountain white fox protector of the demon realm, she gets beaten back to her original form and suffers amnesia at the start, unable even to transform into human shape. Accidentally bumping into the legendary Demon Lord Cang Shizhou, she treats him as a friend for free food, drinks, and protection, little knowing that he has long fallen for her, secretly cleaning up her messes and safeguarding her safety. On the journey escorting Mu Lansheng, a half-breed of the three realms, the celestial clan's millennial conspiracy, along with the secrets of the Cangxuan Sword and the Glass Heart, are exposed one after another. When she suddenly realizes his true identity and wants to run away overnight, she is pressed into his arms by the Demon Lord: "You are this lord's fox, and for life after life you can only be my fox."