Cologne is the great-grandmother of Shampoo and upon Shampoo's return to Japan, she moved to Japan with her and opened the Cat Cafe.
Cologne is a master martial artist and knows many techniques that had been lost to the ages. She is a constant source of trouble for Ranma, because she knows how strong he is and that the would make an excellent fiance for her great-granddaughter. But despite causing so many problems for Ranma, she honestly likes him and has helped him to become a much more talened martial artist teaching he and Ryoga such techniques as the Bakusai Tenketsu, Kachu Tenshin Amaguirken and the Hiryu Shoten Ha.
Cologne also had a relationship with Happosai in the past. He visited her village in China decades ago and fell in love with her. Of course Cologne was much more attractive then, but she did not fall for Happosai's lustful charms. The two seniors have now become rivals and can not stand each other.
The Meaning Behind the Name
Cologne can be broken down to "approve" and "rugged mountain-place" which has no real meaning. The real pun in Cologne's name though, is that all the Chinese characters are named after beauty products, such as Mousse and Shampoo.
Miyoko Asou & Kathleen Barr
Miyoko Asou is known for her elderly roles in Japan. Her other characters include Mary Jane in Candy Candy, and Fune in Sazae-san.
In the OAVs and films Cologne was played by Kathleen Barr, who's other roles include Maetel in Galaxy Express 999, and Morrigan in Night Warriors- Darkstalkers' Revenge. She was replaced by Elan Ross Gibson in the TV series.