Dougan was assigned as Sanzo's attendant before their journey west even began. The young boy became infatuated with the priest after asking why he had been beaten up. Despite everything, Dougan served his master faithfully until Sanzo left on a mission to save Shangri-La. From that day forward, Dougan was determined to prove himself useful to Sanzo on their journey. He fled from the temple, underwent training, and returned years later only to find that Sanzo had already departed. Feeling abandoned once again, Dougan snapped and ran away.
Dougan admired Sanzo's travel companions and wished to possess all of their qualities. To achieve this, he became fiercely loyal like Son Goku, killed a thousand demons in one night, and dyed his hair red with the blood of his victims, resembling Sha Gojyo. For years, Dougan waited at the castle of the clan he had slain, hoping for Sanzo's return so that he could show him how powerful he had become.
Dougan is known for being overly dramatic and spending most of his time making paper airplanes. He took Houran, the daughter of the leader of the clan he had slain, as his personal slave to lure Sanzo Ikkou to his mansion. In the end, Dougan was defeated when the shikigami he placed in his body caused a black hole to form, sucking him in.