Kotoko

Kotoko comes across as an emotionless character, but she can actually have a short temper and becomes very outspoken. She and Sumomo even each other out with Kotoko's calmness and Sumomo's craziness.

Kotoko is far more serious than Sumomo, and thinks that everyone in the Motosuwa household is crazy, with Sumomo in particular. Kotoko's specialty is research, which twice drives the story forward. Kotoko is also programmed to always tell the truth, no matter what, even when it works to her owner's disadvantage. She is serious and often cynical, except when researching something, to the point of being tsundere or cold. Despite her personality, she does eventually grow to care for her new owner and even Sumomo.

Kotoko is 16 centimeters tall with long, dark hair tied in two ponytails tied with two large bells containing her plugin ties. She has fair skin and deep purple eyes. She also has a bob-like hairstyle with blunt-bangs. Kotoko wears a white kimono with a large, red obi-bow in the front and white stockings on her legs.

Kotoko originally belonged to Yoshiyuki and her primary specialty is research.

After meeting Chi, Kotoko came to the conclusion that the latter was insane and clueless. She showed her intelligence by plugging herself into the computer and revealing her name, also revealing her master "kidnapped" Chi, much to Kojima's dismay as, due to her programming, Kotoko cannot lie, even if it would be unfavorable to her master. As a result, Kojima was forced to relinquish ownership of her to Hideki to avoid him erasing incriminating evidence in her.

Each time Chi came under the influence of Freya, Kotoko, like other Persocoms, claim they can hear a "familiar voice" speaking to them. It was never clear who this was, but it is implied to be either Freya or Ichiro. These instances reveal her observations and fascination with Chii.

At the end of the series, Kotoko remains under Hideki's ownership.