An interesting bit of history from one of my favourite shows.

The story goes that creator Haruka Takachiho was with a special guest in science fiction writer A. Bertram Chandler; two studio Nue staffers, Yuri Tanaka and Keiko Otoguro hit upon the idea to bring them to the All-Japan Women's Pro Wrestling match, the match they watched featured a tag team duo known as the Beauty Pair.
While watching Chandler remarked with.
"the two women in the ring may be the Beauty Pair, but those two with you ought to be called 'the Dirty Pair'."
Inspiration hit and Haruka created the Dirty Pair, taking the wrestling named duo into a Sci-Fi setting of which he specializes in.
The Dirty Pair were appropriately named Kei and Yuri after the staffers. The characters in the anime refer to themselves as the Lovely Angels, another reference to Women's Wrestling.
Explains why the Dirty Pair are designed in such a way compared to other female characters of the era.