Jay, a legendary hitman of the American underworld,
accepts a contract from Union, the largest killer organization in North America,
to personally destroy the assassin company founded by his friend, Johnny.

The condition for accepting the job was that Johnny’s life would be spared.
However, due to Union’s betrayal, both Johnny and Jay are ultimately killed.

Yet, by a mysterious power, Jay is reborn in the body of an ordinary young man in Korea.
He then reunites with Johnny, who has been reborn in the body of a young woman.
To take revenge on Union—the ones who murdered them—
the two join forces once more and decide to found a powerful new “company.”