Kang Hasun has the ability to see vagrants, special beings that disguise themselves as humans. They have never caused him any trouble, until one day he is attacked by a vicious group of them. Just as he is on the verge of death, Beom, a tiger vagrant, pops out of his necklace and saves him. With Beom's help, Hasun learns that his family has a deep connection with the vagrants and a secret power that they desire. Can he learn how to control these powers and defeat these villains in time?