Kikuo Toguchi is a journalist and photographer who works for a local television channel, often serving as a cameraman who documents grisly crime scenes and unusual events. His most distinctive feature is his missing left eye, which was removed as a result of wartime injuries and now bears a mysterious engraved barcode in the socket. He typically covers this disfigurement with an eyepatch that frequently changes design, sometimes featuring a simple smiling face, an eyeball, or other patterns. His remaining right eye is affected by cataracts, a condition that slowly and painfully pushes him toward total blindness.

Initially, Toguchi operates as an ambiguous and morally unclear figure, sometimes assisting the police with their investigations while at other times cooperating with the very criminals he is documenting. He is present at the beginning of the story's central events, and through his camera work, he plays a role in revealing the existence of one of the protagonist's alternate personalities to another key character. He is described as a stylish and seemingly carefree guerrilla journalist, but beneath this surface lies a growing darkness fed by the horrors he has witnessed and the personal and professional rejections he has endured.

The character's trajectory takes a dramatic and violent turn upon learning that his remaining eye is failing. This diagnosis acts as a psychological breaking point, pushing him past a moral threshold. Feeling abandoned by friends and betrayed by lovers, Toguchi abandons his role as an observer and embraces his darker impulses. He commits a series of arbitrary murders before orchestrating an elaborate hostage crisis in the panoramic hall of the Tokyo municipal building in the Shinjuku district. His motivations become a desperate mix of nihilism and a grandiosely twisted desire for meaning, as he turns his final act into a televised performance art piece. Using his expertise with media, he holds his victims captive and asks viewers to send in their demands for how to change society, with the horrifying result that requests pour in despite the violence.

In this final stand, he refuses to negotiate with the authorities and demands to speak only with Kazuhiko Amamiya, the multiple personality detective, indicating that Toguchi possesses significant knowledge about the enigmatic group known as Gakuso and a figure named Lucy Monostone. His actions also draw the attention of Zenitsu, another unbalanced and pain-resistant villain who becomes enraged when Toguchi makes sensitive information public. Despite Amamiya's attempt to negotiate, Toguchi's end comes at the hands of another character, who fatally shoots him. In his dying moments, he whispers a cryptic revelation to Amamiya, stating that they are all children of Lucy Monostone, a line that serves to connect his own tragic downfall to the larger, darker mythology of the world he inhabited.