What will happen when a desperate boy who grew up among evil people steps into the world of cultivating immortals? Immortals and demons can be separated by a thought, and life and death are not decided by heaven. Let's see how he goes against the current in this world where humans and demons coexist and evil spirits run rampant, and become a legend.

The legendary former hitman Tarou Sakamoto has thwarted numerous assassins after an enormous bounty on his head was issued. But he cannot seem to catch a break and simply take it easy with his beloved family. A mysterious and infamous figure known as Slur has brought a group of insane death row inmates to Japan, who hold back from nothing to eliminate their targets. Sakamoto is not the only target—the criminals have been assigned to kill various other people, including the new hires at Sakamoto's convenience store, Shin Asakura and Lu Shaotang. The situation escalates even further when the Order, a group of the most skilled Japanese assassins, becomes involved. As the inmates begin wreaking havoc, Sakamoto and his allies must remain vigilant for the sake of everything they hold dear.

This is a world where heroes are created by people's trust, and the hero who has received the most trust is known as - X. In this world, people's trust can be calculated by data, and these values will be reflected on everyone's wrist. As long as enough trust points are obtained, ordinary people can also have superpowers and become superheroes that save the world. However, the ever-changing trust value makes the hero's path full of unknowns...

The top of the immortals, proud of the world, as long as my ancestor An is there, there is the sky. There are three million sword immortals in the world, and they must bow their heads when they meet me. As a sword immortal, I should suppress all enemies in the world. Who claims to be invincible, who claims to be undefeated?