Cologne is the esteemed elder and leader of the Chinese Amazon tribe, known as the Joketsuzoku, and is the great-grandmother of the warrior Shampoo. Her exact age is uncertain but is considerable; the manga suggests she is over one hundred years old, while the anime portrays her as being around three centuries old. In her youth, she was a woman of normal stature and great beauty, a stark contrast to her current, diminutive form. The reason for her shrunken, hunched appearance as an elder is not explained.

Cologne often serves as a detached and amused observer of the chaos surrounding Ranma and his many rivals, seemingly finding joy in watching the comedic turmoil unfold from the sidelines. Despite her constant scheming to secure Ranma as a husband for her great-granddaughter, she holds a genuine liking for the young martial artist and has played a significant role in his development as a fighter. She is remarkably intelligent, cunning, and possesses vast knowledge of ancient lore, magical artifacts, and lost martial arts techniques. While she can be a source of trouble and trickery, her actions are often motivated by a desire to see the tribe thrive and to guide the younger generation.

Cologne’s primary motivation is to ensure the future of her tribe, which she sees as being secured by having Shampoo marry a powerful and worthy martial artist like Ranma Saotome, whom she frequently addresses as "son-in-law" or "bride-groom". To this end, she opened the Cat Café in Nerima, where she, Shampoo, and the hapless Mousse work, using it as a base of operations. She is a contemporary and rival of the ancient martial arts master Happosai. In the anime, a flashback reveals a more complex past, showing a young Cologne secretly loved Happosai, only for him to break her heart and steal a family heirloom, the Nanban mirror. Their present-day relationship is one of antagonism and mutual disdain. She is also a constant torment to Mousse, whose unrequited love for Shampoo she finds irritating, often whacking him with her staff for his troubles.

Though her primary goal is to arrange a marriage between Ranma and Shampoo, Cologne frequently steps into the role of a wise mentor and teacher, imparting crucial techniques to not only Ranma but also his rivals, seemingly for her own amusement and to see how their strength develops. She taught Ranma the Kachu Tenshin Amaguriken (Chestnuts Roasting Over an Open Fire) technique to improve his speed, and later the Hiryu Shoten Ha (Dragon Ascension Wave). She also taught Ryoga Hibiki the Bakusai Tenketsu (Breaking Point). As a character, she remains largely static; a consistently powerful, wise, and manipulative elder from her introduction. Her backstory with Happosai adds depth to her character, but her role in the present is firmly established as the sagelike, scheming matriarch who helps the younger fighters grow while always pursuing her own agenda for her tribe.

Cologne is an exceptionally skilled martial artist whose sheer technique and experience are rivaled only by Happosai. While not necessarily the most powerful in terms of raw destructive energy, her skill level is so high that she can easily defeat top-tier fighters like Ranma without using her full strength. Among her notable abilities is her unique method of locomotion, pogoing on a gnarled wooden staff that also serves as a potent weapon. Her martial arts prowess is vast, including the ability to manipulate water and ice, create whirlwinds by redirecting an opponent's anger, shatter objects with a touch, and fire chi blasts. Beyond combat, she is an expert in arcane lore, Chinese mythology, and identifying and utilizing powerful magical items and pressure points, such as the technique used to make Ranma intolerant of hot water.