Japanese breast size study shows rapid growth in the previously smallest-busted region of the county.

Meanwhile, Japan’s cultural capital, Kyoto, experiences dramatic downsizing.

Japanese cosmetics maker Love Cosme conducts an annual study of bust sizes in Japan, and once it’s tallied its data, it releases a listing of the most common size in each of Japan’s 47 prefectures. In the study’s most recent iteration, which involved 33,813 participants, the researchers found that busts have been growing in the vast majority of Japan’s geographic space, with a startling increase in mammary mass for one prefecture in particular.

First off, the data, collected between January and August of last year, showed a D-cup bust to be the most common, with that being the average size in 27 prefectures, including Tokyo, Hiroshima, and Nagano. Osaka and Kanagawa were among the four prefectures at the top of the scale with an E average, while Kyoto and Nara were among the six at the smallest end with B-cup busts. For the remaining 10 prefectures, such as Hokkaido and Aichi, C-cup breasts were the most common, and no prefecture came out of the survey with an A-cup bust representing the study participants.

The complete list of results is:

#B-cup: Fukui, Kyoto, Nara, Shiga, Oita, Saga
#C-cup: Aichi, Gifu, Hokkaido, Ibaragi, Ishikawa, Kumamoto, Mie, Miyagi, Tochigi, Yamanashi
#D-cup: Akita, Aomori, Ehime, Fukushima, Gunma, Hiroshima, Hyogo, Iwate, Kagawa, Kagoshima, Kochi, Miyazaki, Nagano, Nagasaki, Niigata, Okayama, Okinawa, Saitama, Shimane, Shizuoka, Tokushima, Tokyo, Tottori, Toyama, Wakayama, Yamagata, Yamaguchi
#E-cup: Chiba, Kanagawa, Fukuoka, Osaka

Comparing the most recent results to those from Love Cosme’s 2012 study (which involved 24,819 participants), seven prefectures saw their average sizes go down and 10 stayed the same, with Kyoto experiencing the largest reduction by going from an E in 2012 to a B in 2018, the only three-size drop. Previously D-cup Fukui, Nara, and Shizuoka all moved down two sizes, as did Gifu, shifting from E to C.

On the other hand, the bust size for 30 prefectures grew compared to the 2012 statistics. The largest gain occurred in Saitama, Tokyo’s neighbor to the north, which in 2012 was the only prefecture with an A-cup average. As of the most recent study, though, Saitama has grown to a D bust, the largest gain of any single prefecture (something Love Cosme credits to an increase in average hours of sleep per night for Saitama teen girls over the past few years).

Tokyo itself increased from C to D, and bust sizes in 10 prefectures (Aichi, Fukushima, Hiroshima, Ibaragi, Ishikawa, Mie, Niigata, Okayama, Oita, and Saga) remained the same, compared to 2012.

In closing, it’s worth keeping in mind that in both studies the data was collected by participants filling out a survey, and so the respondents representing each individual prefecture in the most recent survey may or may not be the same ones from 2012. As such, it’s possible that increases or decreases in bust sizes aren’t only being caused by health and diet factors, but also by population redistribution (such as, theoretically, an unusually large number of busty women moving out of Kyoto or into Saitama in the last few years). Because of that, it’s probably best to think of Love Cosme’s survey results as a temporary snapshot of Japan’s ever-changing upper-body topography.

Source: Love Cosme (1, 2) via Hachima Kiko
Top image: Pakutaso