J'rgan was a male Klingon serving in the Klingon Defense Force in the 23rd century. His father was a follower of Kahless's teachings on honor during a time that those teachings were unpopular in the empire, and he impressed those teachings on his son. As an adult, though, J'rgan rejected these teachings, and as a member of the KDF, agreed to act as a spy for those who would pay him for information on his superiors.
As of 2287, J'rgan was assigned to the IKS Gal'tagh under Captain Koloth, and was charged with gathering information about the peace conference with the Federation held that year on Starbase 49. However, when Koloth and the Gal'tagh unexpectedly left the conference, Komor of the Klingon High Council personally charged him with learning the reason for Koloth's actions. J'rgan's subversion was discovered, and Koloth challenged him to a bat'leth duel as a way to regain his honor. The fight quickly resulted in J'rgan's decapitation. (TOS novel: In the Name of Honor)