Shinbo was the original owner of Sumomo, but left her with Hideki after leaving with Takako. He later transfers Sumomo's registration to Hideki, giving him permanent ownership. At the beginning of the series, Shinbo uses Sumomo in an attempt to analyze Chi, and Sumomo is nearly broken in the process, requiring new main memory, and in the manga, a new video card as well. Once Kotoko joined Hideki, she quickly came to the conclusion that Sumomo was mad, with her nonsensical ways.
Voiced by: Motoko Kumai (Japanese), Sandy Fox (English)