Kid is a small robot and serves as the primary interface companion to the protagonist, Kanipan. Designed as a portable partner, Kid does not possess any inherent special abilities but is capable of demonstrating various functions when equipped with tune-up parts created by Kanipan. This reliance on external upgrades highlights the collaborative nature of his bond with the inventor. In conversation, Kid is characterized by a distinct verbal tic, ending most sentences with the suffix deshi.

As an interface robot, Kid acts as Kanipan's constant companion and assistant. Throughout the series, Kid fulfills the role of a practical partner, aiding Kanipan in his daily activities and inventive endeavors. By the events of the second season, five years after the original story, Kid lives with the now fifteen-year-old Kanipan and has taken on the role of the inventor's caretaker, looking after him and managing their household. A significant development in Kid's capabilities occurs when he gains access to a pendant device. Originally brought by a character named Angelica, this device enables Kid to instantly transfer parts and transform, a power that saves Kanipan on numerous occasions.

Kid maintains a steadfast loyalty to Kanipan, supporting the inventor's dream of reaching the highest level of certification. Throughout Kanipan's journey from a young and often failing inventor to a more accomplished engineer, Kid remains a consistent and stabilizing presence. The relationship between the boy and his robot forms the central partnership of the narrative, with Kid often providing a grounding influence as Kanipan pursues his ambitious, and sometimes impractical, ideas.