The blonde bimbo stereotype was created especially for Mihoshi. She is a member of the Galactic Police (her grandfather is the commissioner), and while on patrol looking for Kagato, she gets caught in a warp bubble, and ends up on Earth with the rest of the gang.
Although an utter ditz, she usually succeeds, apparently through blind luck, and shows signs of incredible powers of observation.
Mihoshi's voice actor for the Japanese OAV is
Mizutani Yuko, and for the English dub is Ellen Gerstel (aka Jean Schwartz).