The following article will reveal the origin, history and inner mechanics of the Kaio Ken martial arts technique.
What is the Kaio Ken?
The Kaio Ken is a heavenly martial arts technique taught to Goku by North Kaio.
It is one of Goku’s signature techniques used during the first few sagas of Dragon Ball Z.
The Kaio Ken amplifies Goku’s speed, power, mental acuity and physical prowess for short bursts of high intensity.
In the early episodes of Dragon Ball Z, Goku was killed by his brother Raditz, passed into the afterlife, ran 1,000,000 kilometers (10,000 miles in the English dub) across Snake Way, and then trained with North Kaio on his planet.
Not even North Kaio could fully perfect the Kaio Ken, as it is a very advanced mind-body technique.
Goku eventually surpassed his master.
Terminology of Kaio Ken
Kaio Ken (Japanese Kanji: 界王拳) is pronounced as “Kigh-oh-ken,” not “Kay-oh-ken” as it was pronounced in the original English dub. When spoken properly, the “Kai” in Kaio rhymes with “pie.”
Kaio (界王) can be translated as “Lord of the Worlds.”
Ken (拳) is Japanese for “Fist” or “Hand” and in the martial arts world Ken refers to a particular style or family of techniques.
Kaio Ken thus means “Lord of the Worlds Fist,” or alternatively “Fist of the World King,” and therefore serves as both the signature technique of North Kaio and the name of the Kaio martial arts style in general.
A Kaio is a deity of higher realms that presides over a specific dominion. Each Kaio is a master of their own realm, and beneath them are other lords who rule over their individual sectors or planets.
This system of lord above lord manifests itself from the highest realms to the lowest, like a series of concentric circles, each divided into quadrants.
North Kaio is the ruler of the North Quadrant of the Western Galaxy, and is the lord of Kami, appointed Guardian of the Earth, where Goku lives.
There are other Kaio’s, but it is not known whether they are also able to perform or teach the Kaio Ken.
When was the Kaio Ken Used?
The first time we see Goku use the Kaio Ken technique is in Dragon Ball Z episode 29, while fighting against the Saiyans; Nappa and Vegeta.
Nappa is flying toward Goku’s son Gohan and best friend Krillin to deliver a death blow. Goku is not flying fast enough to catch up to Nappa, so he is forced to use the Kaio Ken technique to intercept the strike.
Goku screams “Kaio Ken!” and is surrounded by a flaming red aura. He propels forward in the sky and punches Nappa with both fists in his spine, mid-flight. Nappa spins around as a result of the blow.
Continuing to surge forward, Goku lands on the ground underneath Nappa, and then catches him with one hand before he makes impact. Goku then tosses his now paralyzed opponent’s body to the ground.
The scene’s immediate aftermath is transcribed here, from the subtitled FUNimation Dragon Boxes:
Vegeta: “What was that just now?! For an instant, his speed and power suddenly increased!”
Krillin: “G-Goku how did you do that? Was that a technique you learned from that Kaio person?”
Goku: “Yeah. It’s called Kaio-ken. By controlling all of the energy [Ki] within your body, you can momentarily amplify it. If you do it right, your speed, power, destructive and defensive forces all increase many times over.”
Krillin: “That’s so awesome! Even after getting that much stronger, you can become many times stronger than that?”
Goku: “Yeah. [But] If I don’t restrain my Ki just right while I’m controlling it, I could kill myself. In short…”
[Flashback to his training on North Kaio’s Planet]
North Kaio: “You have done well to master the Kaio Ken technique, which even I could not handle, to this degree. However, I must stress again that you must not overuse Kaio Ken at your current level. If you mishandle your control, you will end up ruining your body. Do your best to limit yourself to a double multiplier. Remember, using Kaio Ken any higher than that will place too great a burden upon your body. In other words, your body won’t be able to keep up with the Kaio Ken, and it will bite back for what you’re doing to it.”
Goku: “Got it!”
The English version dubbed by FUNimation follows the same basic flow, but misses some important descriptive points, so the original Japanese was referenced here instead.
The Kaio Ken is used over a dozen times throughout the entire series.
How does the Kaio Ken Work?
This is where most Dragon Ball guides stop. They talk about the What and the When. They don’t talk about the How.
The reason most guides to Dragon Ball do not explain how the Kaio Ken works is most likely because the above dialogue is all they have available as reference. This dialogue is as far as the series goes in explaining the Kaio Ken.
But how does the Kaio Ken work, and what are the inner mechanics?
The exact training techniques employed by North Kaio are unknown. All we see is Goku busting through some bricks after he learned it, but not how he actually learned to use it in the first place.
Because of the lack of official explanation, the following explanation for the Kaio Ken represents my best attempt.
Training the Kaio Ken
Recognize that the Kaio Ken is an integrated mind-body technique.
A practice of both mind and body means simultaneously cultivating the mind and tempering the body.
If the body is not trained to a high degree, then even if the mind were capable, the body would falter.
In the case of Goku, tempering of the body involves physical training with a focus on repetition and teaching the body how to react and become integrated with the mind.
Goku cultivated the mind when he worked on proper timing, mental endurance and a sharp focus.
From a metaphysical perspective, by undergoing intense and focused training Goku is able to fill his body on the molecular and sub-molecular levels with more and more energy. In Dragon Ball they call this energy Ki.
Through such training Ki becomes increasingly dense, to a point where it fills up all the cells in the body. The particles of energy are increasingly refined to become smaller and more powerful, even though they fill up the same amount of space.
So the more Goku trains, the more powerful he becomes.
Physical transformations occur at later points in the series, but not now.
Using the Kaio Ken
Analyzing the technique from a Daoist martial arts perspective may produce the following understanding.
The energy is drawn from the Dan Tian (energy field in the lower body, Chinese: 丹田), and sent out to the chest, back, head and four limbs.
The Ki travels underneath the skin and causes the muscles to bulge and the flesh to become thick around the bones.
As the Ki reaches the surface of the body in this dimension it manifests as heat, wind, and electricity.
When Goku employs the Kaio Ken he opens up all the cells in his body and taps into their energy on a molecular and sub-molecular level.
Goku’s cells, molecules, atoms, neutrons, quarks and all other sub atomic particles are opened up and tapped into for a very short amount of time.
The Kaio Ken increases the metabolism of the cells in the body. The cells exert an incredible amount of energy in a short amount of time and are then completely expended.
The cells die and need to be replaced. But this recovery process takes as much time as the normal functions of the body will dictate. So during a battle, the use of Kaio Ken must only be used in desperate times of need.
A correlative explanation to Tibetan “Monk’s Fire” may help.
In this practice monks will wrap a wet cloth around themselves and then sit in meditation in the freezing cold mountains. As they sit, the water in the cloth starts to steam, and eventually the towel becomes dry. Under thermal cameras it can be seen that the monks bodies are much hotter than normal.
The exact science of how the monks do this is still waiting to be discovered. Perhaps they heat up the body by using Ki or by increasing their cellular metabolism via a mental technique. Long distance cold environment runners have been found to use a similar technique.
In the second DBZ movie, The World’s Strongest, Goku uses the Kaio Ken to free himself from the frozen ice of Ebifurya’s attack. He heats up so much that the ice melts and breaks apart.
Having melted the ice and broken free, Goku defeats his opponent.
The Dangers of Kaio Ken
There are repercussions to using the Kaio Ken, because Goku’s Ki is at higher levels than his natural, base form is used to.
Each multiplier of the Kaio Ken increases the metabolic rate and expenditure of the cells. This is why North Kaio warned Goku during his training against the Saiyans to not go beyond Kaio Ken x 2. He said anything else would kill him.
But during the battle, Goku was forced to go to Kaio Ken x 3, and even Kaio Ken x 4 in order to win.
In the Viz English manga, Goku says:
“Oh well… Better to blow myself up than let him do it.”
During his battle with the Saiyans, Kame Seninn was on Kame Island and felt the energy being exerted by Goku. He said the following:
“It’s said that the flame of a candle burns intensely just before it goes out. It seems to me that Goku is tremendously overexerting himself.” Chi-Chi cries back, “Don’t say anything so ill-fated!”
Goku is fighting for his life against Vegeta and says to himself:
“Damn, he’s a tough one… If I don’t finish this quickly–”
And then part of Goku’s body goes into spasm:
“Damn—My body can’t–! My whole body is aching! Sure enough, it looks like performing a times three Kaio-Ken was asking too much… If I dally around, I’ll be the one who goes down first!”
The power of Goku’s Saiyan genetics and incredible inborn quality of endurance are what allow him to persevere.
He gains victory and defens the earth, but his body is completely drained and crushed. Only the miraculous power of the Senzu allow him to recover.
Kaio Ken Koncluded
The Kaio Ken was a useful technique but was phased out as the series continued.
By the time Goku becomes a Super Saiyan during the Freeza Saga he no longer employs short bursts of intense but personally crippling power.
The other technique Goku learned from North Kaio was the Genki Dama.
The Genki Dama works in the opposite fashion to the Kaio Ken. It absorbs energy from within a certain expanse of time and space, and channels it into the cells, filling them with righteous life energy that is aligned with the characteristic of the universe.
A person cannot even use this technique unless they have a pure heart. When using the Genki Dama, Goku’s face becomes very peaceful and meditative.
By contrast, when using the Kaio Ken, Goku’s face becomes angry and intently focused, as if he were expelling a great deal of energy.
The Genki Dama and Kaio Ken are corollary techniques within the same family of Kaio Ken martial art. Goku was the only student of North Kaio’s who learned both.
With these two techniques, one of absorbing and the other of expelling, Goku becomes a super powerful warrior.
Combine these with the Kamehameha energy wave and Goku is nearly unstoppable.