During the Punk Hazard arc, Trafalgar Law swaps Sanji into Nami's body and Smoker into Tashigi's. In spite of them being in bodies not addicted to nicotine, it seems they both still need to smoke. Nami (in Franky's body) even offers Sanji a pack of cigarettes saying something to the effect, "You need them, right?"

When Trafalgar Law swaps everyone, the image shown is some weird heart thing, not swapping their brains. I assume this is some kind of representation of a soul, but if they still need nicotine, maybe I'm wrong. So, what exactly does Law swap? And why do Sanji and Smoker still need to smoke?

3 Answers 3


If you ask any smoker, he will tell you that most of the addiction comes from the brain as it gives the neuro-signals for pleasure when smoking. Most smokers can't quit not because the body demands nicotine, but because of the apparent relaxating effect that is produced by smoking and the habbit that results from it.

Smoking is a recreational drug in public view and tends to work as such.

Edit: And now on how Law's power work. The swap technique that Law uses looks like he is swaping the "hearts" of people, but because they retain their original thoughts, memories and even habbits (like smoking) makes me believe that it's actually their consciousness that is being transfered since all these reside in the brain and not the heart.

Hope this answers your question.

  • You seem to be silently inferring that Law did swap their brains, which is one of the points I am struggling with. Why? Is there evidence in the manga or anime to think so? Is there some line of reasoning? If so, please include this in the answer. Commented Mar 25, 2021 at 19:51
  • It could be as simple as the question answers itself: that because they still need to smoke, it must mean Law swapped their brains and not their souls. But I'd still argue that you should include that in your answer. Commented Mar 25, 2021 at 19:56
  • Obviously, I'd prefer a more in-depth analysis on how Law's powers work, what he's able to control with them, etc., and maybe something about whether souls exist in the One Piece world, but I don't want to force anyone to do an excessive amount of research that they don't want to do. And I do appreciate that you did the real-world analysis of smoking and nicotine. Commented Mar 25, 2021 at 19:58
  • Well, I think nobody knows how Law's power work up to this point. Maybe Oda will give a better explanation in the future. But I will add my opinion on how it works in the answer.
    – RigaCrypto
    Commented Mar 29, 2021 at 6:17
  • "Most smokers can't quit not because the body demands nicotine". This seems to assume that the brain is not part of the body. Addiction from tobacco is both physiological (nicotine lowers the threshold for dopamine release, resulting in stress and anxiety due to the lack of dopamine during withdrawal) and psychological (the habit of taking a cigaret after a meal is hard to quit,...).
    – Taladris
    Commented May 3, 2021 at 1:58

Simple Answer: Law's DF is wired (even kadio annoyed by that), and even a mystery to that point.

It was stated, one of the most usable, power devil fruit in the world.

So, How law can change someone's mind(brain) to another person by swiping their hearts! It ven does seems, it's only the conscious state. And sub part reamins in the brain of that body. (ref: Franky in Chopper's body)

A Heart never can have a mind!

This is a unanswered mystery yet. We've to wait until the real information. Until, you can check some fan theories, analysis on that. Maybe will help to understand better.


I don't think this question can be fully answered, so I'll just list out some possibilities, as well as some evidence for and against.

First Possibility: Law actually swapped not only their brains, but a lot of their internals as well. Sanji in Nami's body claims to be the best swimmer on the crew and thus he has to be the one to rescue the samurai's torso from the sea. But why does Sanji still have his abilities while in Nami's body? It might make sense if Law swapped the internals of the bodies, including muscles.

Where this theory seems to fail: Franky and Chopper's bodies seem to work as normal. Also, when Sanji and Nami swap back, Sanji feels the pain his body went through under Nami after she punches him, saying "My body hurts from a whole lot more than one punch." If the injuries were only skin deep, he likely wouldn't collapse from the pain here.

Second Possibility: Law actually did swap their souls. And somehow, in the world of One Piece, skills and memory are stored in the soul, thus why Sanji still has fighting potential while in Nami's body. And maybe the soul really is stored in the physical heart (Who's to say in a fictional world? Whether it was the actual heart is not important, however, and as previously stated, the physical representation of the swap did not look like a real heart.). And what else is stored in the soul? The urge to smoke, apparently.

Where this theory is weak: If the characters still have access to the actual brain of the body they're in, and thus the memories and knowledge, this would be odd, as they don't appear to have much idea of how to use their abilities. Nami in Franky's body seems particularly inept.

Third Possibility: Law swapped their brains. It is very plausible that the urge to smoke would carry over, then, along with all their memories. Though as to why Sanji retains some physical prowess, there would seem to be no good answer.

The second and third possibilities likely are more credible, as Sanji does struggle a bit in Nami's body, saying at times he can't keep up,etc. But at the same time, he's clearly got too much physical prowess while in Nami's body, so something is definitely off. It could possibly be a combination of the second and third as well.

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