He first appears as Ashitaka's ally, but is later revealed to be the secondary antagonist, wanting to present the Forest Spirit's severed head to the Emperor Mikado so that he could be paid handsomely. It is said the head has the power of eternal youth. He is a member of the mysterious organization Shishoren (eng. the alliance of lords).
Jigo pretends to be a knowledgeable monk and initially helped Ashitaka by giving him information about the Forest Spirit while being pessimistic about the state of the world.
In his next appearance, it's revealed that he's hunting the Forest Spirit with permission from the Emperor and he also has platoons of Riflemen along with Hunters working for him. Jigo gets Lady Eboshi to help him slay the Forest Spirit after telling her she owes him for letting her use his Riflemen to help kill Nago. Jigo and Eboshi manage to track the Forest Spirit to its lake in the middle of the forest and Jigo lets Eboshi kill it, claiming it's best to let others do the work of killing gods. Jigo takes the severed head of the Forest Spirit and tries to flee the destruction that the Forest Spirit's death was inflicting on the world. Knowing that the Forest Spirit's wrath would only be quenched if it reclaimed its head, Ashitaka and San confront Jigo, who claims it'll be over when the sunrise comes and destroys the Night Walker. Jigo tries to fight them off while his men escape with the head. However, that plan fails when the head's container is dropped and Jigo, Ashitaka and San are surrounded by the Forest Spirit's corruption. Left with no other choice, Jigo surrenders the head and the Forest Spirit ceases its destruction.