Keychain | HunterxHunter | Hunter License

A Hunter License is a type of card given exclusively to Hunters after they pass the Hunter Exam, which proves the status of the owner and has multiple benefits. It provides free access to most of the public services and permission to go almost anywhere in the world without a visa. It also grants the ability to kill without facing major legal consequences, although there are exceptions. A Hunter License also grants access to guarded information as well as being an easy way to get jobs. Furthermore, there are collectors willing to buy it for a fortune that would sustain a Hunter's family for generations.

(from Fandom Hunterpedia)

Hunter × Hunter (ハンター×ハンター, Hantā Hantā), pronounced "Hunter Hunter", is a Japanese manga series written and illustrated by Yoshihiro Togashi with two anime adaptations. The first chapter of the Hunter × Hunter manga series was published in March 1998, in Weekly Shōnen Jump.

The story of Hunter × Hunter focuses on a young boy named Gon Freecss, who one day discovers that the father he has always been told was dead is alive and well. He learns that his father, Ging Freecss, is a legendary Hunter. Despite the fact that his father abandoned Gon with his relatives in order to pursue his dreams, Gon becomes determined to follow his father's footsteps, pass the Hunter Exam, and eventually find his father to prove himself as a Hunter in his own right.

(from Fandom Hunter x Hunter Wiki)