Oppai - The Japanese Breasts


What is the true meaning of Oppai? Do you know the different ways of referring to Japanese women's breasts? What are the measures of Japanese breasts and bras? Do Japanese women really have small breasts? Why do Anime characters have big breasts? This and other questions will be answered in this Japanese breast guide!

Recalling that this is a complete and didactic guide, a subject that is a little delicate but important for everyone, not just for otakus perverted and curious. This article is useful for Brazilians who need to buy clothes in Japan and curious people. The summary below will help you navigate this long article:

The Meaning of Oppai

Anime fans or those who delve into Japanese culture quickly know the word oppai [おっぱい] which means breasts or breasts in the Japanese language. What few know is that it is an informal slang or word.

The expression oppai [おっぱい] literally refers to the breast and breasts, while run [胸] is used to refer to the breasts, sometimes figuratively. Already oppai it mainly refers to the physical part of the round and bulky breasts.


The word oppai can be used both to refer to the breast, breasts or breasts in plural or singular. This word can be used by both women and men when referring to women's breasts.

Although it is an informal word, it is not strange to hear newspapers use the expression oppai to refer to breastfeeding or related topics. Women also often talk to each other using this expression.

We don't know if there are specific rules that say that this word is exclusive to refer to women's breasts, but the word itself reminds us of onomatopoeia in boing boing, referring to female breasts. And if we explore the origin we will understand even more why I said that.

Oppai - Japanese Breasts

Word Origin Oppai

It is not clear how the expression oppai in the Japanese language came about. Some believe it came from onomatopoeia paipai (ぱいぱい) that children use to refer to mothers' breasts. So we must remember that oppai may sound a little childish, although it is not necessarily a word used by children.

There are other theories that the word came from ooumai [おおうまい] or idad [いっぱい] which means full, but both seem to be a bit exaggerated. There are records of the word being used in Edo Period, and it is listed as a child word in the Meiji era.


Remember the Oppai Shirt used by One Punch Man's Saitama? How about buying one below?

Ways to Say Boobs in Japanese - wikiHow

What other words do Japanese people use to refer to breasts, nipples or breasts in Japanese? Let's now see a little vocabulary to improve your studies of nihongo. We also have an article on butts in japanese.

What is the meaning of Mune?

Mune [胸] - This word is used to refer to the breasts as a whole, both physically and symbolically, used to refer to every part of the chest such as the lungs and stomach. Usually the word is used run in songs to talk about heart pain and things like that.

Menu is like a second word for heart, since the original word of kokoro heart it is too comprehensive, because it can refer to mind and spirit. Therefore run is a widely used term, probably more than oppai.

Other ways to say Breasts in Japanese

  • ぱいぱい - paipai (child);
  • ブレスト - burusuto (breast);
  • 母乳 - bonyuu (mother's milk);
  • ボイン - Boin;
  • カップ - kappu (cup);

Other synonyms are:

  • Chibusa [乳房] - breasts, breast, udder;
  • Kyoubu [胸部] - breasts, breasts;
  • Munaita [胸板] - breasts, breasts;
  • Chichi [乳] - Milk, breasts;
  • Muneniku [胸肉] - Breast meat (usually chicken breast);

Vocabulary related to boobs in Japanese

Below are some useful words for women who want to measure sizes or buy accessories related to breasts like bra and others.

  • Bra - ブラジャー (burajya);
  • Chest - 胸 (mune);
  • Breasts - おっぱい (oppai) looking like slang;
  • Cup, Cup - カップ (kappu);
  • Tits, breasts - ぱいぱい (paipai) another kind of children's slang;
  • Bust - バスト (basuto) from English bust;
  • Cleavage - 谷間 - tanima (also means valley, ravine, abyss);

Pettanko, Paizuri, Bakunyuu, Kyonyuuu

There are other Japanese words to refer to breasts. There is even a word to refer to the crisis of having small breasts or large breasts. We have written some articles that will help you understand these factors, we recommend reading below:

Oppai - Japanese Breasts

Measurements and sizes of bras in Japan

Breast size is calculated from A to K, with A being the smallest size. Some countries have small differences in measurement, as in the USA there is size AA, however, the system is the same. It is worth making it clear that this measurement is proportional to the size of the body.

The first thing we can do to determine the size of the breasts is to measure the entire bust with the breasts, then subtract by the size of the bust measuring below the breasts, the remaining value is the size of the cup or cup (CUP). (top bust - under bust = cup).

SizeCup / CupUnder BustTop BustBrazilian Size
THE 10.2cm 63 ~ 6777-8738
B 12.0cm 68 ~ 7282-9240
Ç 15.0cm 73 ~ 7787-9742
D 17.5cm 78 ~ 8292-10244
AND 20.0cm 83 ~ 8797-10746
F 22.5cm 88 ~ 92102-11248
G 25.0cm 93-97109-11150
H 27.5cm 98-102114-11652

It is worth remembering that the measures of the cup or glass in Japan is different from Brazil. Brazilians usually measure from the bust to the back, thus giving a high value above 78, whereas the Japanese do is to divide the two measures mentioned to arrive at an exact size of the breasts.

The image below shows how the busts are measured, and an image showing the size of the Japanese busts, however, with the letters

Oppai - Japanese Breasts

The larger the size of the breasts, the larger the bowl. However, it is not enough to know this to buy the bra size. The table below can help you choose the appropriate size for your bust:

Under BustTop BustBra size
63 ~ 6777 ~ 79A65
63 ~ 6779 ~ 81B65
63 ~ 6781 ~ 83C65
63 ~ 6783 ~ 85D65
63 ~ 6785 ~ 87E65
68 ~ 7282 ~ 84A70
68 ~ 7284 ~ 86B70
68 ~ 7286 ~ 88C70
68 ~ 7288 ~ 90D70
68 ~ 7290 ~ 92E70
73 ~ 7787 ~ 89A75
73 ~ 7789 ~ 91B75
73 ~ 7791 ~ 93C75
73 ~ 7793 ~ 95D75
73 ~ 7795 ~ 97E75
78 ~ 8292 ~ 94A80
78 ~ 8294 ~ 96B80
78 ~ 8296 ~ 98C80
78 ~ 8298 ~ 100D80
78 ~ 82100 ~ 102E80
83 ~ 8797 ~ 99A85
83 ~ 8799 ~ 101B85
83 ~ 87101 ~ 103C85
83 ~ 87103 ~ 105D85
83 ~ 87105 ~ 107E85
88 ~ 92102 ~ 104A90
88 ~ 92104 ~ 106B90
88 ~ 92106 ~ 108C90
88 ~ 92108 ~ 110D90
88 ~ 92110 ~ 112E90

Average Japanese breast size

Have you ever wondered what the average Japanese women's breast size is? Are they smaller than the average for Brazil? Where do you have smaller breasts? Below I will leave a short list with statistics:

Average breast size in Japan:

  • 5.3% of the Japanese represent size A or smaller;
  • 20% from the Japanese represent size B;
  • 26.3% of the Japanese represent size C;
  • 24.1% from the Japanese represent size D;
  • 16.2% from the Japanese represent size E;
  • 6% of Japanese represent size F or larger;

Average breast size in Brazil:

  • 30% of the Brazilian population is size A and B;
  • 33% is size C;
  • 19% of size D;
  • 16% are E, F and G;

Where do most of these Japanese women concentrate? Below we will leave a list where the majority of these Japanese are located according to size. Let's look at the average size of each province.

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

How did we arrive at these results? - This survey is carried out according to the amount of sales of bras, lingerie and other women's products.

Oppai - Japanese Breasts

Do Japanese really have small breasts?

We just saw about the average Japanese breast size, did you come to any conclusions? Do Japanese women really have small breasts? In fact, Japanese girls' breasts are not as small as people think.

In the research we saw that only 5% of the Japanese are with small size [A]. The big problem is that this measure is proportional to the size of the body, the Japanese women are thin and small by nature, which reduces the breasts.

Some research shows that in the last 20 years, there has been a surprising increase in breasts compared to 1980 where more than 50% of Japanese women were size A.

Another survey of 400,000 women shows that neither Brazil was among the 15 countries with the largest breasts, nor Japan was among the 15 countries with the smallest breasts. In fact, Brazil has an average of 30% of Brazilians with size A and B.


It may even seem that the Japanese are beating Brazil in this average disclosed here. However, this average is proportional to the size of the body, we take the average from the bowl by subtracting the upper bust with the lower bust.

Therefore, even though 30% of the Brazilian population is classified as having small breasts, due to the size of their body, the breasts can reach up to 20 cm. Not to mention that research like this is never 100% accurate, since it is not possible to do research like that with the entire population.

Oppai - Japanese Breasts

Why in Anime have big breasts?

I think the reason why Japanese women have big boobs in anime is kind of obvious, to attract the male audience. But if the standard of Japanese beauty is skinny women, why do anime have big tits? Or why the Japanese in anime have big eyes and colored hair?

These are unanswered questions, they are anime clichés. When anime shows big tits, panties and attractive positions, this is called fanservice. The purpose of a mangaka when creating his work is to attract all kinds of people, for this reason you can find sizes for all tastes.

The fact that Japanese women have too big breasts may be successful with men in Japan, but in real life there may be prejudice from other Japanese women. We have seen this portrayed in some anime.

Oppai - Japanese Breasts
A giant anime action figure with giant breasts

Oppai Korean Meaning - Korean Breasts

Some search Google for oppai in Korean, but are probably confusing with honorific of treatment and oppa slang. Usually used by women to refer to an older man.

Koreans recognize Japanese slang oppai that can be written [단어]. If you want to refer to breasts in Korean, we can use [유방] [가슴] [댕 이] [방댕 이] [궁디], but unfortunately I am not an expert in the Korean language to explain each of these words. One tip is to play them on Google Image to learn how Koreans interpret the meaning.

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