Takeshi is a destiny-marked young man bearing the "mark of the serpent," a sign identifying him for persecution by the Kikuchi clan. These descendants of Japan's original families view Takeshi as an existential threat. His life is defined by trauma, particularly the murder of his father ten years prior, an event that continues its psychological haunting. This personal tragedy collides with a vast cosmic conflict when the Kikuchi clan recognizes him as the prophesied individual destined to confront and potentially destroy them.

He is revealed as the living embodiment of Atman, representing the fundamental energy of the human spirit. This spiritual significance plunges him into a nightmarish struggle against ancient forces of darkness, specifically the god Susanoo-no-Mikoto, who seeks rebirth and threatens to engulf the world. Takeshi's journey navigates a landscape of supernatural threats, including demonic entities and hungry ghosts, forcing him to grapple with his own identity and purpose.

As the narrative unfolds, Takeshi faces possession by Susanoo's chaotic power, compelling him to confront the catastrophic potential within himself. This internal conflict culminates in a critical choice: wield the god's power for annihilation or embrace a path of spiritual renewal and rebirth. His decision carries profound consequences for the cosmic balance. His psychological state manifests visually during trance-like sequences, depicted walking through abstract, bleached landscapes where only elements directly interacting with him materialize, symbolizing his disconnection from reality and immersion in spiritual turmoil.