Kazuyuki Asakawa is the central protagonist in the narrative of Ring: Saishūshō. He is a journalist in his early thirties, working as a magazine reporter for a major newspaper company. Physically, he is described as being nearsighted and is almost always seen wearing his silver-rimmed glasses, a consistent trait that underscores his role as an observer and investigator.

In the context of the story, Asakawa is a family man. He is a widower raising a young son named Yoichi. This paternal relationship is a core aspect of his characterization, as his primary motivation shifts from professional ambition to the desperate protection of his child once they are both ensnared by the supernatural threat. Initially, his pursuit of a strange series of unexplained deaths is driven by a reporter's instinct for a major scoop. He approaches the case with the skepticism of a newsman, initially suspecting a scientific explanation, such as an unknown virus, rather than a supernatural curse. This lack of caution leads him to inadvertently view the cursed videotape, which condemns him and, through his subsequent actions, his son to die within seven days.

Once the reality of the curse becomes clear, Asakawa’s personality shifts from that of a detached journalist to a desperate and sometimes anxious father. His resolve is tested as he races against time to save his family. His role in the story is that of the primary investigator and the emotional anchor for the audience. He is not a detective or an occult expert; he is an ordinary man forced into extraordinary circumstances, relying on his research skills to trace the tape's origin.

Key to his investigation is his relationship with Ryuji Takayama, a former classmate and university lecturer. Asakawa seeks out Ryuji for his intellect and unorthodox, fearless demeanor. While Asakawa is prone to moments of doubt and fear, Ryuji provides the cold, analytical logic and harsh encouragement needed to push the investigation forward. This dynamic is crucial, as Asakawa does not possess any special abilities or psychic powers; his strengths are his persistence, his professional ability to gather information, and his deep-seated determination to protect his son. His development throughout the story is the evolution from a career-focused reporter to a man willing to face terrifying truths and make harrowing moral decisions for the sake of his family. Following the events of the initial curse, his fate is a tragic one, as his attempts to save his family ultimately fail, leading to a car accident that leaves him in a catatonic state before he passes away.