Tamiya Iemon is the central human character in the Yotsuya Kaidan story arc. He is introduced as a ronin, a masterless samurai, living in poverty. His background is defined by his low social standing and his desperate ambition to escape a life of destitution. Initially, he is presented as a man motivated by love for a woman named Oiwa, but this affection is shallow and quickly gives way to his more dominant traits of greed, selfishness, and cruelty.

Iemon’s personality is a study in hypocrisy and a gradual descent into pure villainy. At the outset, he appears more sympathetic than his counterparts in traditional kabuki theater, but this veneer is thin. His primary driving force is an insatiable desire for wealth, status, and personal comfort, which he prioritizes above all else, including human life and familial bonds. He is calculating and manipulative, capable of performing acts of extreme violence and deception without visible remorse. After his circumstances improve, he becomes increasingly impatient with his sickly wife and the burden of their child, revealing a profound lack of empathy and a cold, pragmatic cruelty.

His role in the story is that of the villainous protagonist whose actions drive the tragic plot. Iemon’s journey is one of moral ruin. When Oiwa’s father opposes their marriage due to Iemon’s status as a ronin, Iemon murders the old man and then pretends to seek revenge for the killing, manipulating Oiwa into returning to him. After a period of time and the birth of his son, Iemon grows tired of his impoverished life with Oiwa. He is seduced by the promise of wealth and a new marriage to Oume, the granddaughter of the wealthy Kihei Ito. Iemon becomes complicit in Oume’s scheme to disfigure Oiwa with poison, using the resulting horror as a pretext to abandon her. His cruelty escalates when he instructs his retainer, Takuetsu, to rape Oiwa so he can divorce her on the grounds of infidelity, and to murder her if she resists. When his plan is exposed, Oiwa’s shock and despair lead to her accidental death. Showing no grief, Iemon then murders a servant to frame him as Oiwa’s secret lover, and has the bodies, along with his own infant son, nailed to a board and cast into a river to fake an elopement.

Key relationships define Iemon’s villainy. His relationship with Oiwa is the central tragedy; he views her first as an object of desire, then as an obstacle to his own advancement. His marriage to Oume is purely transactional, based on her wealth and his ambition. He has no loyalty to his servants, whom he tortures and kills without hesitation. His relationship with his retainer Takuetsu demonstrates his ability to corrupt others to do his bidding.

Iemon’s character development is a stark line of moral descent. While he begins with a base level of dishonesty and violence, he grows progressively more monstrous. He crosses a series of moral event horizons, from murder to conspiracy to torture and finally to the orchestration of his wife’s death and the murder of his own child. By the story’s end, he has transformed into a completely remorseless figure, so consumed by his own ambitions that he shows no reaction when the vengeful spirit of Oiwa kills his new family.

In terms of notable abilities, Iemon is a samurai, trained in swordsmanship and combat. He uses these skills not for honor, but for murder and intimidation. His most notable ability, however, is his cunning and his capacity for manipulation, which he uses to deceive Oiwa and conspire with the Ito family. Ultimately, his skills are futile against the supernatural wrath he unleashes, and he is eventually confronted and killed by Satou Yomoshichi, a wronged man seeking vengeance for Iemon’s crimes.