Kotoko, a laptop-sized persocom crafted by Yoshiyuki Kojima, boasts advanced specifications surpassing standard models like Sumomo. Originally Kojima’s creation, her ownership is forcibly shifted to Hideki Motosuwa after Chi’s kidnapping, triggered by Kotoko’s inability to lie or conceal facts—her programming compels unfiltered honesty, even at her owner’s expense. This transparency becomes instrumental in exposing pivotal secrets, such as Kojima’s role in Chi’s abduction.

At 16 centimeters tall, she features dark lavender twin ponytails fastened by bell-shaped ornaments, matching lavender eyes, and a doll-like silhouette with blunt bangs. Her white kimono and bold red front-tied obi accentuate her petite frame. Her demeanor diverges from typical persocoms, balancing Sumomo’s exuberance with a composed, sharp-tongued pragmatism.

Adept at research, Kotoko drives investigations through data decryption, technical analysis, and database infiltration. Her tsundere-like personality wavers between detached sarcasm and understated concern, gradually warming to Hideji and begrudgingly coexisting with Sumomo despite dismissing their home’s disorder. Supernatural undercurrents surface when she references an ambiguous “familiar voice” during Freya-related events.

Programmed to prioritize truth above all, her blunt disclosures fuel both tension and humor, clashing with social niceties. Once Kojima’s tool for manipulation, her forced transfer to Hideki marks her evolution into an autonomous ally. By the narrative’s end, she retains her pragmatic edge while adapting to life under Hideki’s ownership, her loyalty subtly solidified without compromising her unyielding nature.