It is said that as Japan began to receive cultural influences from the West in the modern era, people began to perceive the breast as a sexual impression. In the past, a woman's attractiveness was found in the ankles peeking out from the sleeves of a kimono or the neckline of a collar, and women were not so conscious of the fullness of her breasts or the slenderness of her waist.

One of the reasons why Japan was influenced by Western culture in terms of its perception of the breast was the importation of many Westernized clothing items after World War II, which rapidly promoted the Westernization of the Japanese people.

The oldest magazine on brassieres, Shufu no Tomo, describes how to make a bra under the title, "How to make a nipple bra to enhance your figure. The purpose of this instruction is to help those with large breasts who are having trouble because their kimonos are becoming thinner and thinner. The following is a brief description of the recipe.
Around 1940, it is noted that the breasts should be moderately breasted to keep them beautiful. For those with too large breasts, a simple design is used, and for those with too small breasts, multiple layers of lace are used or cotton is added to create a more complex design and give them fullness.

Around 1950, with the rapid economic growth of Japan, women entered the labor market and Western-style clothing took root among the general public. The reasons why women who entered the workforce chose to wear Western-style clothing were not only because of its functionality and economy, but also because of the psychological changes it brought about. The experience and opportunities that women experienced in Western-style clothing and the understanding of the advantages of Western-style clothing and Western-style clothing helped promote the spread of Western-style clothing among women.
Around 1960, it was noted that underwear itself was becoming a fashion trend.

Since bras were introduced in Japan as a way to dress and look beautiful in Western-style clothing rather than for health reasons, the need for bras was widely recognized as women gained the right to freedom to express themselves and as Western-style clothing became popular among the general public.