Sunday, February 9, 2014

The Science of Manga - Part 1

The Science of Manga - Bleach
Written by: ClayDragon

If there are two things that interest me, they’re science and manga. It occurred to me that the two need not be mutually exclusive, so I’ve decided to do an article dedicated to applying real-world science to the world of manga. I’m not simply going to explain how things work in relation to the laws of physics within the manga, I’m actually going to use the laws of physics that our world relies on to explain things. As such, if you have any questions about science in a manga series that you’d like me to answer, simply leave your question in the comments below. For my first article, I thought I’d tackle one of the main concepts of Bleach:

Aren't they pretty?

Can we build a Zanpakuto?

 Simply put, yes. Well, sort of. It depends heavily on the Zanpakuto itself. It’s easy to make a replica of a Zanpakuto – just go to any convention and you’ll see any number of model swords (In fact, check out this video to see a replica of Zangetsu being made). I’m more interested in the special abilities of the Shikai form and whether we can imitate them. For this article, we’re assuming that the person wanting to make a Zanpakuto has access to the tools and knowledge needed to build one. Because some Zanpakuto have flashier abilities than others, I’ve split this article into sections – Easy, Medium and Hard, based on how difficult it would be to build the Shikai. Also, just because the section says ‘Easy’ doesn’t mean you can build it in your shed (although if you do, send pictures because I will be very impressed).

Tony Stark, cave, box of scraps, blah blah blah you know the rest.


These are the bog-standard Zanpakuto – either they’re not very fancy, or have no real abilities to speak of. For example, Renji’s Zabimaru and Ikkaku’s Hozukimaru are pretty simple when you look at them. Because they can easily be built by someone with the proper equipment, I’m not going to spend a lot of time on them.

Sorry guys, but they aren't that impressive.

The one thing I would like to touch on is the ‘self-healing’ aspect of the Zanpakuto. As Kurotsuchi has told us, a Shikai can be fixed by having the owner pour their reiatsu into the sword, and from that it can repair itself. Since we can’t actually do that, we need to look for the next best thing.

A self-healing material is something that can repair damage done to it, by a variety of methods. Scientists have been able to create a metal coating that can fix itself after taking damage. It works by containing capsules that are mere nanometres thick, and these capsules can contain anything from a liquid that prevents corrosion to a polymer that could seal a crack. As such, if we were to coat our sword in this liquid, any damage done to it could be fixed by the capsules. The only problem is that there might not be enough capsules to fix more serious damages, but it’s a start. Besides, most cracks on our sword would be caused by small fractures getting bigger over time due to stress, so if the capsules could heal the fractures before they expanded, it wouldn’t be a problem.

In this picture, the capsules contain a gallium-indium mixture which seeps into the cracks in the gold surface and repairs it. Not quite reiatsu healing, but hey ho.


Alright, now we’re getting somewhere. These are the Zanpakuto with abilities that you could theoretically recreate, although your bank account might be empty by the time you’re finished. Perhaps the two easiest ones to build would be Tobiume, Momo’s Zanpakuto, and Ashisogi Jizo, Kurotsuchi’s Shikai.

Say what you want about Momo, at least her Shikai doesn't have a baby's face on it. Although she hasn't reached Bankai yet, so it could still happen...

Firstly, let’s look at Ashisogi Jizo. So far, the only known special ability it has is that it contains a poison in the blades that paralyses anyone stabbed by it. Given that the blade itself would be fairly easy to create, the only real difficulty in building this Zanpakuto would be the poison. Fortunately, a quick search tells us about Curare, a group of paralysing toxins used by indigenous South American tribes. It causes death by relaxing the muscles and paralysing the respiratory system, meaning victims would die of asphyxiation. Whilst this doesn’t have exactly the same effect as Ashisogi Jizo’s poison, it’s pretty damn close. I could go on about poisons taken from frogs and so on, but I’m going to stop before people suspect me of being a serial killer.

SUFFER! SUFFER, YOU MONSTROSITY! But yeah, Kurotsuchi's poison is kinda like this.

Tobiume is another one that would be relatively easy to make, even with its ability of projecting fire out of the tips. The closest approximation we have to this is a flamethrower, but we could just as easily use an aerosol can and a lighter to simulate the effects. It would be a relatively easy task to fill the hilt of the Zanpakuto with ignitable gasses, and have a valve that would open when a button on the hilt is pushed, allowing the gasses to flow out of holes on the end of the sword. At this point, a spark would need to be produced in order to ignite the gasses. Just in case the fire goes backwards and burns up all the gas in the hilt, a pressure backflow preventer could be used to ensure that the gas only flows outwards.

Warning: They may not remain your friends for long.

So far, so good, but let’s take a look at some even more powerful ones.


At this point, we’re sort of going off the rails a little. With respect to these Zanpakuto, the technology to emulate their abilities is either available but really expensive, currently in development, or will maybe be available in the next 10-20 years. With this in mind, the two Zanpakuto that we’ll look at here are Byakuya’s Senbonzakura and Ichigo’s very own Zangetsu.

So majestic....

To start with, we’ll look at Senbonzakura. Given that there’s no reasonable way to sharpen cherry blossom petals to the point where they can cut into flesh, we’ll have to look for other options, and that’s where nanobots come in. Nanobots are tiny robots that are invisible to the naked eye, and operate on a molecular level. The science of nanotechnology is still very much in its infancy, although the fact that nanobots can affect things at a microscopic level means that it has the potential to be a very lucrative field. It’s theoretically possible to build an army of nanobots into a sword, and then release them to attack your enemies upon command. You could even go so far as to program them to assume the shape of a cherry blossom petal if you wanted.

Just to give a sense of scale to that nanobot, it's clinging to a single red blood cell. Kinda looks like a Metroid, doesn't it?

Finally, let’s touch on Zangetsu. Whilst it’s physically impossible to fire a wave of pure energy out of a sword, we can actually get fairly close. For this, we need to go to lasers. A typical red laser pointer uses 5 milliwatts of power, but that’s nowhere near enough to emulate the effects of a Getsuga Tenshou. A 2 watt laser is capable of setting things on fire and burning skin, and it’s classified as a Class 4 laser- the most dangerous kind. Of course, it’s illegal to sell preassembled Class 4 lasers.

Not that that stops some people. You can pick up a 2 watt laser online for about $600 (about £366).

And these are only 0.75 watt lasers. The Force is strong in these ones.

A laser this powerful can burn right through a planter, and will do a decent job on leather. Of course, we could keep increasing the power, but the size of the equipment will also increase, to the point where it would be too big to fit in a sword. For now, let’s stick to our 2 watt laser. Whilst the body of Zangetsu was being built, we could mount our laser in the tip, along with some wiring connecting it to a button at the hilt. When the button is pressed, the laser shines its beam at whatever is in its path. Of course, 2 watts is still nowhere near as powerful as a Getsuga Tenshou, but it could still do some serious harm – especially if you shine it in someone’s eyes.
Of course, there's always one idiot who doesn't wear goggles....


Sadly, there are some Zanpakuto that can’t be replicated, regardless of the technology used. We simply can’t create a sword that can also become a flying manta ray, or one that can actually be used to heal people (unless we use nanobots again, but even then these things still might not be possible). This is also true for pretty much every Bankai – the only one that could feasibly be made is Tensa Zangetsu, and that’s only because it has the exact same abilities as its Shikai form.

Seriously, Kubo. What the hell were you on?

The only alternative option we have is to put severe limitations on how these Zanpakuto work, and make as best an approximation as possible. For example, the closest we could get to creating Ryujin Jakka is probably just to make a sword-shaped soldering iron, but then the maximum heat would only be about 450 degrees Celsius, which is nowhere near hot enough. 

Yep, that is definitely hot enough to melt solder. And tungsten.

So it can be done?

Well, yes. Of course, it would be very expensive and time-consuming, and it’s very unlikely that you could build one in your garden shed. But more importantly, the technology exists for us to replicate the effects of a Shikai to a pretty good degree, if not perfectly. Granted, it’s maybe not as mysterious or awe-inspiring when you know the ins and outs of how it works, but the sheer fact that we can make self-repairing swords that shoot fire or poison people or fire lasers out of their tips more than makes up for it.

If a man wearing a bow tie says so, it must be true.

ClayDragon is currently studying Physics at university, and is constantly bewildered by it. The main method of contacting him is his Gmail account at The alternative is his Skype account at kyleroulston1993. When not playing games or reading, he can be found with his head in his hands whilst trying in vain to understand quantum physics. He also has difficulty with crystals.


  1. I am disappointed by you calling Renji's shikai unimpressive. It's more creative and has more potential for battle than Ichigo's sword ever had.

    1. I think you're missing the entire point of this article.