Anime enthusiasts can arguably agree that Masashi Kishimoto's Naruto was one of the best anime in the Otaku-verse. Created in 1995, it created a long story that lasted about 15 years before it was over, and is still being enjoyed today. Undoubtedly the anime went worldwide, and has been enjoyed by many.
One of the greatest techniques that featured severally in the series was the Eight Gates (Hachimon) technique. Used by only a few ninja: Might Duy, Might Guy, Rock Lee, Kakashi Hatake, Shinno and (in the Boruto series which features the generation after Naruto's) Metal Lee.
The first person we see using this forbidden technique is Rock Lee against Gaara of the Sand during the Chunin exams. Apparently, it was first used by Might Duy, who taught it to his son, Might Guy, who thought it to his favorite student, Rock Lee.
Lee and Guy are arguably the most human characters in the series - very passionate, respectful and honest. In addition, both have little (Guy) or no (Lee) aptitude for Ninjutsu and Genjutsu - they cannot express chakra physically, meaning they can't breathe fire or use hand seals and jutsu. Guy is able to use Ninjutsu to an extent, even though he cannot be compared to Kakashi, or even Naruto.
Instead they utilize only taijutsu - physical techniques - to fight. Lee is constantly trying to prove that with only taijutsu, he can become a splendid ninja. In the end, Guy taught him this technique to be used as a trump card.
So what are the Eight Gates?
These are limiters within the body that limit the flow of 'chakra' (call it energy if you will" within the body. According to the anime,. the human muscles can only use 20% of their chakra or body potential, which is an inbuilt feature that prevents our bodies from overexerting and wearing out.
It s obvious that the technique is indeed hard to learn, as Kakashi Hatake is surprised to learn that 13-year old Lee who was still a Genin or low-level ninja was able to open 5, making Kakashi term him 'a genius of effort'.
With a great amount of work and effort, Might Duy was the first person identified to have opened these gates - after 20 years of practice. He taught it to his son, and later died using it to save his son's team from being killed by the Seven Ninja Swordsmen of the Mist (he killed four of the swordsmen)). He opened all eight gates, which is certain to kill both the user and the victim (except if either possesses strong regenerative abilities).
Even though the Eight gates isn't exactly a 'technique', it is considered a forbidden technique, or Kinjutsu, because there's a reason why the body has these limiters in the first place. It is considered a self-sacrificing technique, because the effects range from extreme fatigue and torn muscles to death.
So let us go over the Eight Gates and see the effects of usage
The usage of the opening of these gates is known as Hachimon Tonkou. Guy gives Lee a self-rule behind the usage of the technique -to protect the life of a loved one. (Awww).
The First Gate: The Gate of Opening (Kaimon)
Opening the first gate, which is located in the left side of the brain, removes the mental inhibitions on the use of more chakra than the body 'recommends', allowing the user to perform the Primary or Front Lotus (Omote Renge). This technique tires the user afterwards.
The Primary Lotus begins with a strong upward kick (a series of kicks were required in Gaara's case) to send the target in the air. Lee then performs the 'Dancing Leaf Shadow', coming behind the target and then automatically wraps his bandages around the target before driving them in a pile-driver style into the ground. At the instant of impact, Lee disentangles and jumps off.
If performed successfully, I think this is a certain kill technique.
TRIVIA: Kakashi Hatake was able to open only this gate, and it was probably whn he used his Sharingan to copy Lee's use of it. Probably.
The Second Gate: The Gate of Rest/Healing (Kyumon)
Located in the right side of the brain, it helps increase the user's strength and speed, re-energizing the body from the strain caused by the opening of the First Gate and use of the Lotus.
The Third Gate: The Gate of Life (Seimon)
It is located on the Spinal Cord. From the opening of this gate, the massive amount of chakra is visible on the user's body - they emit a bluish aura (due to the physical outpouring of chakra), their pupils disappear and their skin turns red due to the increased heart output and blood flow. The also bare their teeth (due to the pain their bodies are in or just to make it look cool?)
Opening this gate allows Lee to begin the Hidden/Reverse Lotus (Ura Renge), a move characterized by a Primary Lotus-style upward kick followed by a barrage of heavy punches.
The Fourth Gate: The Gate of Pain (Shomon)
It is located on the Spinal Cord. Opening this gate creates a green aura around the user.
Lee opens the gate immediately after he opens the third. He then begins the Hidden Lotus. This is probably to further increase his strength and speed. Opening this gate tears his muscles and his nose also begins to bleed.
At this point, Lee's movements causes tremors on the ground. Also, when he opened the first gate, several kicks were required to send Gaara into the air, but upon the opening of this one, only one kick sent Gaara flying into the air. Lee's movements were also impossible to track by the normal eye - Kakashi had to use his Sharingan.
The hits were so fast, Gaara's automatic sand shield defence was unable to follow with it.
The Fifth Gate: The Gate of Limit/Closing (Tomon)
It is located in the abdomen.
Lee opened this gate to add even more strength as he delivered the last two punches, probably so as to ensure the opponent's defeat. . A direct one to Gaara's stomach, and then he held on to Gaara's falling body with his bandages, drawing him back for the final blow (which appears to be by both his right hand and foot).
After this, Lee's right leg suffered a compound fracture. Gaara survived by converting his gourd into sand and using it as a cushion. Unable to walk due to extreme fatigue and crushed bones, Lee's left Leg and Arm were crushed by Gaara's Sand Coffin.
Although, ordinarily, this technique should, under normal circumstances, defeat or even kill the enemy.
The Sixth Gate: The Gate of Joy/View (Keimon)
It is located in the stomach.
Opening this gate increases every ability and allows the user to perform the Morning Peacock (Asa Kujaku). The power creates vortexes in water, and the punches are so fast, the friction created with the air produces flames which spread out akin to that of a peacock fan, which is responsible for the name.
The aura around the user glows green, and the victim is covered in a fiery aura as the final punch sends them to the ground. Like the others, the technique is certain to kill under certain circumstances.
The technique can also be delivered at a distance, sending balls of fire at the target.
TRIVIA: In the anime, Rock Lee created his own version of the technique, calling it 'Morning Chicken' or Asa Niwatori.
The Seventh Gate: The Gate of Shock/Wonder (Kyomon)
It is located just below the stomach.
On opening this gate, the users sweats blue sweat from every single pore of the body, and this sweat evaporates instantly, causing a blue aura to envelop the user, which can be mistaken for chakra. The user's muscle fibers are completely ripped apart, meaning that any touch or movement causes pain. We see Might Guy use it against Kisame Hoshigaki and Uchiha Madara.
But the effects are impressive, as the user creates a cannon of pressurized air which resembles a tiger with a single punch. This probably looks like a tiger because the Tiger hand sign and a unique hand seal of a lion are formed as it is released. The technique is called Daytime/Afternoon Tiger (Hirudora).
The pressure condenses to a singe point as it moves, and can be released on command, causing a huge explosion and a shock wave.
The Eight Gate: The Gate of Death (Shimon)
It is located at the hear and the opening of this gate is termed the Eight Gates Released Formation (Hachimon Tonko no Jin).
This gate as manually opened by puncturing the chest right above the heart with their thumb to allow chakra flow in there. At this, the user's hearts pump at its maximum capacity, allowing them power hundreds of times greater than they (or anyone) can use, however brief the usage time is.
The user is covered by a red aura created by a stream of blood (Chi no Joki) coming from the user's pores and hair. The opening of this gate causes the user's body to continually heat up from the inside until the body is reduced to ash. Thus, it certainly kills the user.
Opening this gate allows the user to perform two techniques:
EVENING ELEPHANT (SEKIZO): This is a continuous barrage of five punches, called 'steps or feet' with each foot faster than the one preceding it. It creates a cannon of pressurized air akin to that of an elephant's leg, causing damaging destruction to the opponent.
The first punch alone creates massive craters on the ground. In the anime, when Guy uses the first step against Madara, his lower arm bones are crushed in a compound fracture, preventing him from continuously using it. He tries again however, and is able to continuously use it until all steps are completed.
NIGHT GUY: This is the final blow, and is a technique that was unbeknownst to Rock Lee, Guy's protege. He begins the technique by saying "Build Up", and the stream of blood forms into the appearance of a red dragon
Shouting 'flow' or 'charge', he dashes at such supersonic? speed that the space around him is distorted, making the victim unable to dodge or block the attack. Guy finishes it with such a powerful kick, the target's body could be completely destroyed, and a shock wave is created.
Madara Uchiha was able to survive this: perhaps it was as a result of his Sage mode or his Regenerative abilities. But even Madara was very much afraid for his life, as he coughed up blood, stating that Guy had almost killed him.
However, such a huge kick caused such a recoil that the bones in leg used for the kick was crushed instantaneously.
Opening the Eight Gate left guy at the brink of death, as his body was about disintegrating to ash. Luckily, Naruto was able to stabilize his life forcing his Yin-Yang release, even though that leg remained permanently damaged.
TRIVIA: Usually, Guy names his techniques by the time of day followed by the animal the attack has a resemblance to. But he makes an exception for 'Night Guy', meaning that he has turned into the dragon himself.
I hope the explanation was well detailed, and I do hope you enjoyed the visual aids. I used a laptop, so in the Japanese names, I missed quite a few diacritics. Sorry for that;)
Enjoy!
Never knew you were into anime as well