In Japan, there are numerous comics, games, and cartoons that depict females with exuberantly large breasts. So common is this image that your average run of the mill female character has an average cup size of  C or larger.  Japan is known for it’s many sexual kinks, some of which actually have formal names. Listed below are the actual names to classify the various sizes of breasts and to which the large-breast-obsessed community as a whole now go by.

Oppai – breasts (tits)

Nyuu “milk” ( – lit: milk)

This is milk defined as any fluid that is expressed from the mammary glands of mammals. It is not to be confused in definition with the milk that you buy from the store, that would be  gyuunyuu “milk” (牛乳 – lit: cow milk). The second meaning  of Nyuu, which is “breast”, refers to the milk producing glands of mammals, not human females specifically. Although the term may work adequately standing alone to define breasts, most Japanese would use “oppai” instead.


Ookinyuu “big breasts” (大乳 – lit: huge milk)

alt Dekanyuu  “big breasts” (デカ – lit: huge milk)
alt Ookii Oppai formal wording for “huge breasts” (おっぱい – lit: huge tits)
alt Dekapai vulgar wording for “huge breasts” (でかぱい – lit: huge tits)

This classifies normal big breasts. For the most part your average slender female with a full C – D cup would be in this range.


(Note: “Ookinyuu” is my personal label for this size as this would keep in line with the Japanese kanji system and naming convention used with all the other labels. It is also more common to hear them use the word “ookii” when describing big breasts anyway.)


Kyonyuu “large breasts” (巨乳 – lit: very large milk)

Describes breasts that are larger than the average range of big breasts, but are still within the boundaries of normal female development. The upward limit of this range is when the breasts are close to the size of the female’s own head. Breasts this size are extremely rare on slender females but can be attained through cosmetic surgery. This often applies to gravure idols, pin-up models and porn stars who benefit career wise from having larger than average breasts. One will however see this more commonly with plus sized females who are naturally well endowed. A few noted women in this rage are listed below.

September Carrino
Penelope Black Diamond


Bakunyuu “exploding breasts” (爆乳 – lit: exploding milk, bursting milk )

Large breasts of a proportion where each breast has a volume close to, or slightly larger than, the females’s own rib cage. The upward limit of this range is marked by each breast being close in size to the female’s full torso.  By realistic means this size is only achievable through very extreme cosmetic surgery. Currently only a numbered few women have been able to achieve this land mark size and are listed below.

Beshine (aka Mayra Hills)
Chelsea Charms
Minka XXX
Casey James
BB Guns
LOLO Ferrari
Maxi Mounds

Also note that there have been extremely rare cases of breasts being this large naturally on slender females. This is due to a rare medical condition known as gigantomastia or virginal hypotrophy and is not linked with normal female development. Noted examples are below.

Angelique Mwisi – Congo
Xiao Wei – China
Yesica Johanna – Dario Echandia Neiva, Colombia
Pilma – Phillipines
Julia Maria – Peru
Isabel Bacol – ?
Isabelle Lanthier – Quebec,  Canada


Chounyuu “ultra-breasts” (超乳 – lit: ultra milk)

Breasts whose size is at the limit of human imagination but must be at minimum larger than the female’s full torso. Breasts this size are currently not possible in real world application.