Earth youth Su Luo unexpectedly transmigrates to another world. On the verge of death, he is rescued by Tu Shan Hong Hong and bound to the "Heaven and Earth Guardian System." From then on, he remains in the fox demon territory of Tu Shan as a human, becoming Tu Shan Hong Hong's "adopted son."

The system's tasks continuously strengthened his bond with Tu Shan Hong Hong, from initially being cautious and ingratiating to gradually becoming dependent on and being depended on in their daily interactions. At the same time, he also went from being unfamiliar and tentative with the young Tu Shan Ya Ya and Tu Shan Rong Rong to becoming partners. With their companionship and "challenges," he gradually improved his strength with the help of system rewards, unlocking spiritual affinity, mastering basic breathing techniques, and even being able to understand the fox demon's final words.

In this world where humans and demons are separated, Su Luo, aided by the system, slowly grows up on the red land of Tushan. He witnesses the strength and gentleness of Tushan Honghong, and through repeated trials, he gradually understands his feelings for her that go beyond those of a "sister." Even with the conflicts of the demon realm and the prejudices between humans and demons ahead, he is determined to protect this homeland in his own way, to protect the red-clad fox demon who took him in, and ultimately, to live a life together with her.