Lemon Sunomono, whose real name is unknown, is the spy shown and the deuteragonist in Crayon Shin-chan: Fierceness That Invites Storm! Operation Golden Spy. She cheated Shinnosuke by betraying him, she said that "We need to help Action Mask and get the Megahegaderu", however her mission was to help the evil queens of Republic of Sukashipestuan. When she realized her mistake, she got united with Shinnosuke and destroyed all dreams of the evil queens and her parents.
In the end She & Shinnosuke foiled the plans of Narao and Yusuru by forcing them to eat the remaning Megahegaderu II and she and Shinnosuke ate it themselves which caused them to swell up with gas into giant balloons and destroyed the queens facility by releasing a huge fart. Later, when they were about to leave, Lemon told Shinnosuke her real name, which surprised the latter. The two then parted ways, with Lemon developing strong feelings for Shinnosuke.