Did Nami undergo a breast operation by Chopper? ;-)


All joking aside!

How could an 18 year old girl's breasts grow so large within 2 years? After the time skip, Luffy became 19 and Nami turned 20. I know that in the world of One Piece, everything is possible, but why did the producers change her breasts?

This cannot be a coincidence:

From a comment on Facebook

  • 6
    TVTropes: Art Evolution. It's not uncommon for a long-running comic or animated show to change character designs over time. It can often be a result of personnel changes in the production staff, however I don't know enough about the staff of this particular show to say if this is the case here.
    – Philipp
    Commented Feb 21, 2015 at 19:28

3 Answers 3


Oda answered this question himself in Volume 36, chapter 342. Nami's breast grew so much, because she was still young and in her growth phase. Especially with the two years timeskip, they had plenty of time to grow!

Reader: Good day, Oda-sensei. You know, that Nami-chan is so gorgeous!!! That beauty, that figure! I'm already swooning ♡ By the way, when you compare her to the Nami-chan in Volume 1, haven't her breasts grown somewhat? by Saori-chan

Oda: Yep. I get this a lot. But when you consider that she's only 18, she's still in her growth phase. She's got more room to grow! I'll give it my best!! (←?) And Robin's only 28! I'll give it my best!! (←?)

After I ended up reading more of the SBS answers, more measurements were revealed. So as we are all curious as to the question how much they have grown, I will additionally post those in the answer, Nami's sizes!

In Volume 6, chapter 49 Nami's Bust/Waist/Hip (BWH) measurements are revealed to be 86/57/86.

Reader: When the question came up about Nami's measurements, you promised to tell us sometime. So when are you going to tell us?!!

Oda: Hehe. I have made a friend that comes in quite handy for this. His eye is quite accurate. It's the "weird chef", who can tell a girl's measurements with just one look, Sanji-san!!

Sanji: Shitty guy! I'm not "weird"!! It's "love", I'm a "cook who loves"!! Oh but, you called me. I get it, leave it to me. Nami-san's cute, isn't she. She also has style to match. Now, let's take a look... B 86! W 57! H 86! No doubt about it!! But she's so cuuuuute. She's definitely a thief. But I still like her!!

Later in Volume 37, chapter 353, which was still before the timeskip, it was revealed that her bust size had grown to 95, making her new BWH measurements 95/55/85.

Reader: Hi, Oda-sensei! In Volume 36 you were saying that Nami's breasts had grown in size from years ago, so what are her 3 sizes now? I'd bet that every man in the country is dying to know this, so don't hold out on us!

enter image description here
Nami: Height 169 B 95 W 55 H 85. Robin: Height 188 B 99 W 59 H 89

Later, in Volume 42, chapter 406, which was again before the timeskip, Oda confirmed that Nami's and Robin's breasts were I cups.

Reader: I am "Sogeking-ko", a proponent of all healthy young boys everywhere! Healthy young boys of this country!! Remember the question in the SBS of Volume 41, asking about Nami-san's cup size?! According to my rotoscopic vision, Nami-san's under bust size is 65. So her regular bust size of 95 would make her an I cup!!! (donnn) That's HUGE!!! I'm a D cup... Boys... can you accept this answer??

Oda: Well, I must say I received a lot of answers to this question from my female readers. Thank you for your detailed and in-depth explanations. But you know, the boys aren't gonna read any of these complicated, difficult answers, so I'm just gonna report on the most common result! Nami and Robin are I cups. Wow.

Finally, in Volume 69, chapter 686, after the timeskip, her new size were revealed to be 98/58/88, J cup. It seems like she had grown a bit more. I wonder when her growth phase will end.

Reader: About the mystery of Nami-san's New World bust size from volume 66, I would like to provide my opinion as an employee at LADIES' INNER. Nami-san's bust size is most likely a "J Cup". There is a possibility that she may have even grown bigger than this. ...If my calculations are correct, her band measurement is 63cm, and her bust is 98cm. If we were to use these measurements, she would end up being a "K"; however, right now in Japan, there is no such thing as a "K" cup. She'd have to order from overseas. Oui, in other words, non-standardized!!! Well, personally, I'd say that Nami-san is a "Nami Cup". (Boiing)

P.N. Shimizu Chageburo's secret fan

(Translator's Note- LADIES' INNER is a Japanese female underwear chain store.)

Oda: Alright. Boys, the day has finally come. This fire that readers started on volume 66. Thank you all for submitting these countless letters. Sanji-kun! Has your nosebleed stopped yet!? Now, give them the presentation!

Sanji: Yeah... sorry about last time. So it's Nami-san and Robin-chan's current 3 sizes, right? They did in fact grow in size, but don't be tricked!! In these 2 years, what really improved is their "sexiness"!

Nami- B: 98 (J Cup), W: 58, H: 88

Robin- B: 100 (J Cup), W: 60, H: 90

Disclaimer: I am no expert on women's sizes and measurements, so if I had made a wrong interpretation somewhere, please forgive me.


I doubt there is a legitimate plot based reason for this, and it's more to do with giving more fanservice to the audience and perhaps the animators refining the character design over time.

  • Not sure if this is just a coincidence, but Nami became 20 after the time-skip. Considering that Robin had boobs from the beginning, it might be related to Japan's coming-of-age concept. Before the time-skip she was traditionally considered a minor, hence small boobs and after the became an adult, hence big boobs, like Robin-sempai. Commented Feb 22, 2015 at 0:38
  • 2
    if you actually look at the series before the timeskip they grow considerably from beginning of manga/anime to right before timeskip. This really probably has to do with fan service for one but more importantly the target audience probably grew to include older audiences.
    – Quikstryke
    Commented Feb 23, 2015 at 15:55

For body size her breasts are far too large to have not been enhanced. They get so large due to maturity, but usually only going up a cup and a half to two cups in size, and a lot of this is also determined by body mass. With her body size and figure she would have not naturally grown breasts that large without outside aid.

Granted I am speaking from a real life perspective, and with a toon you can do all sorts of illogical body proportions. I think this is mainly to attract male readers who for the most part don't care unless it has boobs and a tight butt. XD


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .