Nakasumi is the top toy developer in the world. He is the victim of theft by Drakken and Shego in "Crush". Fortunately, Kim recovers what was stolen, and in return, Nakasumi gives her a ride in "A Very Possible Christmas" and "So the Drama", the latter once again is a major part of the plot. At first, it appears Nakasumi can understand yet is unable to speak English, but eventually it is revealed he can indeed speak English, but prefers to whispering in Kyoko's ear. To avoid using Japanese, the series' crew had Nakasumi whisper to Miss Kyoko for her to translate. One of Nakasumi's characters, Z-Boy, makes several cameos as toys and posters.