Skymark Airlines came under fire from the cabin crew's labour union, which said the super-short skirt -- with a distinctively swinging sixties look -- barely covers wearers' thighs.
"We're concerned that the design of this uniform may cause problems," including sexual harassment, the Japan Federation of Cabin Attendants said in a statement late last month.
"The airline is saying the uniform is meant to attract more customers, but this shows the company is treating women like a commodity," it added.
Comments posted on the union's website said attendants would not carry out their duties effectively owing to fears about leering stares or customers shooting pictures up their skirts with a mobile phone.
The airline, which disputes the union claims, plans to introduce the uniform as a temporary promotion for the launch of domestic routes its Airbus A330 planes in the spring.
The carrier could not be immediately reached on Tuesday.
But last week, Skymark president Shinichi Nishikubo told reporters: "We won't impose the uniform on any of the cabin attendants who refuse to wear it."
"It is disappointing that the outfit designed in part for the ad campaign is being seen in a distorted way," he added.