She was graduated from Tokyo Women’s Christian University and married to a wealthy textile mill owner’s son, Ken Mori. In 1951, she took classes at a local dressmaking school and began an atelier in the Shinjuku district in Tokyo. It was three years later, Hanae Mori opened her own boutique in Ginza at Tokyo. She began her career by designing clothes for over three hundred Japanese film movies.

In 1961, she traveled to Paris and visited Coco Chanel that completely changed her direction in fashion and started the ready-to-wear line.

In 1965, she presented her first line in New York City known as “East Meets West”. She also adopted butterfly as her signature that caught Vogue’s attention. At home she was given the task to design uniforms for Japan Airlines’ air hostesses. The first uniform was worn from 1967 to 1970, the second, was in mini-skirts and caused a sensation, was worn from 1970 to 1977. The third one was worn from 1977 to 1988.

Her contemporary mix of western-Japanese designs had gained her a lot of success and sought after by the celebrities.

It was in 1977 she opened an haute couture showroom in Paris’s Montaign Avenue. She was accepted by Chambre Syndicale de la Couture Parisienne later that year, and was the first Asian designer being invited.   

In 1985, she designed the costume for Madame Butterfly for Milan’s La Scala theatre. Her intricate design and details won her the 150 costumes for Cinderella, a ballet of Paris Opera.

In October 1989, Hanae Mori received the highest honor, Chevalier de la Legion d’Honneur by the French President, François Mitterrand. It was also her 35 years of being a designer, she held an exhibition in Tokyo during that year.