Asato Ichijo, also known by the honorific Ichio, is the grandfather of Takuma Ichijo and a central antagonist in the Vampire Knight series. He holds the position of a Level B aristocratic vampire and serves as the powerful head of the Vampire Council, also known as the Council of Elders, which governs much of vampire society. Physically, Asato has pale blond hair similar to his grandson but possesses icy blue eyes instead of green. Despite being described as very old, he maintains the appearance of a man in his late thirties or forties. He is often seen wearing formal clothes, reflecting his status and personality.

At his core, Asato Ichijo is a cold, calculating, and ruthless individual who believes that the ends justify the means. His primary driving motivation is a deep-seated fear and intense dislike of Pureblood vampires. He views their immense, inherent power as a fundamental threat to the established social order of the vampire world. Consequently, his central goal is to dismantle the Purebloods' authority by any means necessary. He orchestrates schemes to have Purebloods turn on one another and destroy each other, hoping to reshape vampire society with the Council, and by extension himself, in absolute control.

In the story, Asato plays the role of a primary political antagonist who seeks to manipulate the most powerful Purebloods for his own ends. After the death of Juuri and Haruka Kuran, he takes a young Kaname Kuran into his care, not out of benevolence, but in a calculated attempt to become Kaname's guardian and thereby control him. When Kaname refuses, Asato instead sends his own grandson, Takuma, to Cross Academy with the explicit mission of spying on Kaname and reporting his activities back to the Council. His scheming runs deep, as he becomes involved in the阴谋 of Rido Kuran. Asato actively supports Rido, hoping that Rido will succeed Kaname as the head of the Kuran family, believing this chaos will lead to the Purebloods' mutual destruction. His influence even extends to the human world, as he is shown to be in league with the President of the Hunter's Association, conspiring together for mutual gain at the expense of the Purebloods.

The most significant relationship in Asato's life is with his grandson, Takuma. While he appears to care for Takuma on some level and expresses a desire for him to inherit his position on the Council, his ambition ultimately overshadows any familial affection. He treats Takuma as a tool, a pawn to be placed near Kaname. This leads to an irreconcilable conflict between them, as Takuma's genuine friendship with Kaname clashes with his grandfather's ruthless orders. Asato's other key relationship is with Kaname Kuran. He outwardly shows respect, bowing and addressing him as Lord Kaname, but this is a facade that barely conceals his deep-seated animosity and his long-standing desire to dominate him.

Asato's development in the series is defined by his unwavering commitment to his goal, culminating in his downfall. In a final confrontation, he reveals that he knows Kaname is the original ancestor of all vampires, yet he still declares his actions to be righteous and blames Kaname for the chaos in their world. Before he can finish, his grandson Takuma steps forward, stating he does not believe the ends justify the means. Takuma then kills his own grandfather, ending Asato's life and his reign over the Council.

In terms of abilities, Asato possesses the standard traits of an aristocratic vampire. This includes accelerated healing, advanced intelligence, and a greatly slowed aging process. While his specific aristocratic powers are not detailed, he demonstrates significant enhanced strength, as seen when he effortlessly snaps the neck of the former head of the Hunter's Association. His age, demeanor, and political power inspire fear and command respect from nearly all other vampires.