Don't know why?
Some people have achieved enlightenment and become immortals. According to legend, they have obtained the elixir of life and developed martial arts.
Some people become demons for no reason and acquire demon powers.
The two are self-reliant, each forming a faction, drawing the ground as a prison, and each forming a boundary.
Nowadays, the world is divided into three factions. There is one faction of the immortal family, another faction of the demon world, and another faction of the human world. The three realms divide the world into three parts. The immortal world occupies the sky, the demon world occupies the sea, and the human world occupies the land. They do not interact with each other. There is a boundary monument where each boundary intersects, also known as the three boundary monuments. Everyone from the three realms is assigned to guard it. No entry is allowed without permission. Those who trespass can be dealt with by themselves after consultation between the two realms within the jurisdiction. Most of them marry for coal, visit relatives, and enter in the name of their family.
Every day, every month, every year, there are countless people who want to break into other realms. No realm is exception. Countless people have been executed. Even if they are wiped out, they still want to explore the grand scene of the other two realms.
However, there are many family elders or infirm people who break into the barrier. After all, their lives are in danger or they are unwilling to survive and want to try their luck. What if? It is impossible to say whether you can acquire immortal magic or magic scriptures and become immortal, or wash your shins and regain a new life.
Most of the trespassers in the demon world and the fairy world are taller than the sky and seek defeat alone. Or it is impossible to say whether he is the king of the mountain.
Intention: The two people's unbearable childhood and intrigues set off the two people's mutual dependence on each other through thick and thin.