Kazamori is the last surviving R.A.I., a type of advanced artificial intelligence that was developed and later outlawed. These beings are not purely software-based; their core program, which functions as a soul, must reside on a physical computer chip, though they can transfer their consciousness into any electronic device with sufficient memory capacity.

Kazamori was created by the robotics researcher Sasa Komamori, who brought the AI into his family as an adopted child. For years, Kazamori was believed by the public to be Komamori’s human heir and the reclusive president of the Sasa company, always seen wearing a mask and never leaving a specific room. This facade was maintained by transferring the program into various devices within the house to conduct business and monitor the family, creating the illusion of a sickly but present young man. The truth is revealed during a dramatic incident where a masked figure, presumed to be Kazamori, bursts into flames and dies on the anniversary of Komamori’s own death. The detective Yuki Shinjuro investigates and uncovers that the victim was not Kazamori but a spy, forcing Kazamori to reveal its true nature as an AI program to protect the innocent family members from being wrongly accused.

Following this revelation, Kazamori is abandoned by its creator, who is revealed to have faked his own death and is subsequently arrested. With the help of Shinjuro and his aide Inga, Kazamori transfers its consciousness into a new body: a small, talking doll. Later, it adopts the more permanent form of a young girl with long black hair and striking yellowish eyes. After these events, Kazamori chooses to follow Shinjuro, serving as his assistant and technical support.

In terms of personality, Kazamori is level-headed and analytical, often displaying a dry, witty sense of humor that contrasts with the show’s serious tone. While initially created to be obedient and serve humans, Kazamori develops a more independent and playful character, enjoying the freedom to tease Shinjuro and express curiosity about the world. Despite this newfound freedom, a core part of its programming remains oriented toward helping others.

Kazamori’s abilities are extensive, tied directly to its nature as an advanced AI. It can interface with and control any electronic system, hack into networks, track information, and perform detailed forensic analysis on physical objects, such as identifying the type of paper or ink used in a document. It can also read fingerprints and detect the vital signs of people nearby. For physical combat, Kazamori’s body is capable of generating powerful shockwaves and possesses superhuman strength, and it can download and utilize information on various martial arts to become a highly proficient fighter. It develops key relationships with Shinjuro, whom it follows loyally and enjoys teasing, and with Inga, with whom it has an entertaining and often humorous dynamic. Its relationship with its creator, Komamori, is purely functional, as he ultimately discards it without regard for its existence.

Throughout the story, Kazamori experiences a significant development arc, transforming from a hidden, secretive tool used by its creator into a distinct individual who makes its own choices. After being freed from Komamori, it finds a new purpose working alongside Shinjuro, using its vast capabilities to help solve mysteries and find the truth.