The Yuanyang fold is an ancient fold that records the love relationships between creatures in the three realms. It was originally in charge of the Shushui Immortal Lord. At that time, the immortal soul of Shuishui Immortal died, and some unscrupulous immortals took advantage of the chaos to steal the mandarin duck fold in an attempt to change their relationship. Unexpectedly, an accident occurred, and half of the red threads in the mandarin duck fold were scattered to the three realms. In order to calm the turmoil, the emperor of heaven ordered the successor Qinglu Immortal to take the sacred tree branches and the mandarin duck tree guardian spirit fox to the three realms to retrieve the scattered red threads, so that the lovers could finally get married. Unexpectedly, Immortal Qinglu rescued a dying monster with his kindness as soon as he arrived in the monster world...