Hiten Mitsurugi-ryū (飛天御剣流, Flying Heaven Govern Sword-Style) is an ancient kenjutsu style from the Sengoku Jidai, developed to allow a single samurai to defeat numerous foes single-handedly created by Hiko Seijūrō I. Practitioners of this style use a combination of immense speed and agility, battōjutsu, and acquired, observation-based pseudo-clairvoyance that permits a practitioner to anticipate an opponent's movements. Both offensive and defensive maneuvers are executed with minimal movement in order to increase a practitioner's ability to counter-attack and to conserve energy. The Hiten Mitsurugi is designed to be able to take down several opponents at once. It's so powerful that even though Kenshin's training was incomplete, he was one of, if not the most contributor to the Ishin Shishi winning the revolution.

The style commonly has the user keep one hand on the sheath at all times and also stresses two-step attacks in order to ensure that the practitioner is never off guard while executing said attacks. Arguably its most well-known trait is the surreal speed practitioners of this style use in battle (known as Shinsoku, or godspeed), allowing the user to accelerate, maneuver, and strike at speeds most eyes are unable to properly follow. This allows the user to close considerable distance in seconds and strike down the enemies before they can react in time. Despite each successor to this style becoming true masters of its teachings and skills, rarely have any of them been able to use this style to true perfection and bring out its full potential. Only Hiko Seijūrō I and XIII (and in the anime only Amakusa Shōgo) who are able to surpass the generic limits normal limits of this style, such as going beyond god-speed without the need of battōjutsu strikes, letting them accelerate to speeds faster than the human eye can detect.

Hiten Mitsurugi-ryū has been known by very few people in history due to the fact that it has only passed on from master to apprentice, with each apprentice taking the life and special mantle of his master as well as the name Hiko Seijūrō. The style typically has only one master and one apprentice alive at any given time because the ōgi of the style, the Amakakeru Ryū no Hirameki, is typically passed on in such a way as to kill the previous master (though the apprentice is not informed of this beforehand). When the student inherits their master's titles, they also gain an heirloom weighted cloak that when worn permits a master to strength train with nothing more than day-to-day movements, thereby continuously keep up their peak conditioning. However, due to Kenshin's early abandonment of his training, he did not receive the cloak because his master was still alive. .

Due to its tremendous power and speed, Hiten Mitsurugi-ryū has been nicknamed "The Black Ship of the Land" in that it would almost certainly secure absolute victory for whichever side might wield it in a conflict. In light of this probability, the practitioners of Hiten Mitsurugi-ryū have historically maintained independence of any and all political entities, stressing highly the importance of wielding its expertise in the name of their fellow man. All generations of practitioners receive a great deal of insight regarding the human condition from the school's teachings. This includes instruction regarding the relativism of morality and the idea that perceptions of good and evil are not absolute; a potentially "good" human being can have any number of beliefs that may not mesh with those of the practitioner without necessarily being wrong. Other core tenants of the style include the idea the art of swordsmanship ultimately amounts to nothing more than a way to kill other human beings, regardless of the practitioner's intentions or beliefs, and that the Hiten Mitsurugi-ryū should never be used to improve a practitioner's social standing, acquire wealth, or obtain political power. Finally, while heirs are encouraged to protect the defenseless and less fortunate, the Hiten Mitsurugi school ultimately permits it's practitioners to execute individuals whom they deem to be truly deserving of death.

Additionally, the immense force and energy required to perform many of the Hiten Mitsurugi-ryū's moves can take a cumulative toll on the body of the user. According to doctor Takani Megumi, the style is essentially a "superman's sword art", and to use it effectively in the long term apparently requires an abnormally powerful body. Normally, those who properly conditioned themselves during the training of this style developed the extraordinarily developed and highly resilient built, like Hiko Seijūrō XIII and his exceptionally well-muscled physique, necessary to use the style without suffering from it's debilitating side effects even with regular usage. Himura Kenshin, having left his training early, prevented his body from maturing properly to use this style to its full potential, leaving his body underdeveloped with a slender and lithe frame that began experiencing this degradation after mastering the Amakakeru Ryū no Hirameki. After using the technique only seven times, he caused irreparable damage to his muscle tissue, preventing the user from using the godspeed and by extension the advanced techniques of the Hiten Mitsurugi Ryu. Another side effect of training in this style is that it functions as an apparent "fountain of youth" in that it either extends the wielders lifespan and/or it retards the aging process. Kenshin, for instance, at nearly thirty years old, looks almost no different from the way he looked while in his late teens and his master, Hiko Seijūrō XIII, is 43 years old but looks exactly the same as he did when he was in his mid twenties.

• Ryūtsuisen (龍槌閃, Dragon Hammer Flash) - From a position higher than one's opponent (usually initiated by a powerful jump), one uses the momentum of the fall to strengthen a two-handed sword swing that brings the blade down on the opponent's head or shoulder.
  • Ryūtsuisen ● Zan (龍槌閃・惨, Dragon Hammer Flash: Disaster) - Beginning in the same way as Ryūtsuisen, the user positions the sword as to initiate a downward stab to the head instead of a downward swing. Kenshin is first shown using this against Shigekura Jūbei.
• Ryūkansen (龍巻閃, Dragon Coiling Flash) - Most effective used as a counterattack against a thrust or charge, one sidesteps a forward-moving opponent and moves past them. In doing so, one spins in a full circle, adding momentum and centrifugal force to the strength of the sword swing, which is then aimed at either the opponent's back or the back of the neck. The first two kanji used can also be read as tatsumaki, a term for "waterspout" or "tornado", and is often written with two different kanji used for "ryū/tatsu" (龍巻 or 竜巻).
  • Ryūkansen ● Tsumuji (龍巻閃・旋, Dragon Coiling Flash: Whirl) - One of the variations of Ryūkansen, Ryūkansen Tsumuji, like it's other variations, is most effective as a counter attack (seen when used to defeat Sawagejō Chō: Cho-the Sword Hunter),But can be used as an offensive attack.Unlike the Original, Ryukansen-Tsumuji involves a forward-Horizontal spin in a drilling motion like a torpedo.
  • Ryūkansen ● Kogarashi (龍巻閃・凩, Dragon Coiling Flash: Wintry Wind) - An alternate version used in Kenshin's Five Hit Combo against Shishio. Involves a single small side-step coupled with a 90 degree pivot turn inward and a back handed slash that quickly blasts the foe away; unlike the original version which is a full 180 degree full spin and slash. The Ryukansen-Kogarashi is the quickest of the four variations, however, the weakest as well. It is the ideal Counter Attack when dealing with a faster or unreadable attack (as seen when used against against Han'nya of the Oniwabanshu, due to his 'Shin-wan Spell'.
  • Ryūkansen ● Arashi (龍巻閃・嵐, Dragon Coiling Flash: Storm/Tempest) - A variation of the normal Ryūkansen, this technique places the swordsman in a full rolling somersault slash while attacking, making It an effective Counter Attack against Downward slash attacks.
• Ryūshōsen (龍翔閃, Dragon Soaring Flash) - The opposite of Ryūtsuisen, Ryūshōsen is a rising attack meant to strike the jaw from below. For additional power, one uses one's free arm to apply force to the back of the blade and utilizes a powerful upward jump during the attack. Originally this move was designed to slice into the opponent's chin and kill them, but Kenshin has since modified the technique to strike with the sword's side; consequently, Senkaku, Shishio and Aoshi have all survived the attack, though the former was instantly knocked out by it.
• Ryūtsuishōsen (龍槌翔閃, Dragon Hammer Soaring Flash) - A combination of Ryūtsuisen and Ryūshōsen, Ryūtsuishōsen begins with the powerful jump and supported upswing of Ryūshōsen, giving the leap enough power to pass one's opponent in mid-air, and on the returning drop, Ryūtsuisen is performed. it is unknown if this move can be performed effectively without using a sakabatō, as the initial Ryūtsuisen would already be fatal if landed correctly with a normal katana. It can also work the other way around at times, where the Ryūtsuisen performed first instead, followed by a reversal-slash styled Ryūshōsen, in the case of Jump Super Stars, Jump Ultimate Stars and J-Stars Victory Vs.
• Ryūsōsen (龍巣閃, Dragon Nest Flash) - A massive flurry of strikes delivered to the opponent. The sheer speed of the slashes makes this technique difficult to counter or defend (Seen during Kenshin's battle against Sagara Sanosuke). There is an alternate version called:
  • Ryūsōsen ● Garami (龍巣閃・咬, Dragon Nest Flash: Gnawing) - A technique that which targets the foe's head.
• Doryūsen (土龍閃, Earth/Land Dragon Flash) - A ranged attack, Doryūsen strikes an opponent outside of the user's range by striking the ground and sending earthen debris at said opponent with knockout force.
• Kuzuryūsen (九頭龍閃, Nine-Headed Dragon Flash) - A dashing attack that uses Shinsoku (Godspeed) to simultaneously strike all nine vital spots on the foe's body from a normal kendō stance, as each of these nine points are the main targets for different swordstyles (only different styles target different ones). It is said to be undodgeable and nearly unblockable, and is taught as a prerequisite for the succession technique. It is also Hiko Seijūrō XIII's signature move. Users who are faster than the Hiten Mitsurugi, however, are able to evade the attack, as seen with Sōjirō. The strength of the move's "nine heads" will differ greatly depending on the speed, force and even weight of the user. Kenshin's Kuzuryūsen is powerful, but is countered at one point by Yukishiro Enishi, due to the speed being matched, while Hiko's Kuzuryūsen easily overcame Kenshin's due to Hiko's weight advantage. And Hiko's God-like Strength allows him to instantly down the immense Fuji despite such a huge weight disadvantage and not being able to perform the attack at Godspeed (Shin-soku) due to the wearing of the Heirloom weighted cloak.
  • The nine heads of the targets are in counterclockwise while looking towards the target from the user's view:
    • Karatake (唐竹/幹竹, Tang Bamboo/Tree Trunk Bamboo) Aimed at above head with downward strike: 壱 (ichi, one)
    • Sakagesagiri (逆袈裟切り, Inverted Kasaya Cutter) Aimed at right shoulder diagonally: 弐 (ni, two)
    • Miginagi (右薙, Right Mower) Aimed at right arm's center from the side: 参 (san, three)
    • Migikiriage (右切上, Right Cutting Upward) Aimed at right arm's bottom/right wrist diagonally: 肆 (shi, four)
    • Sakakaze (逆風, Inverted Wind) Aimed at groin area from below via upward stroke, or straight from front: 伍 (go, five)
    • Hidarikiriage (左切上, Left Cutting Upward) Aimed at left arm's bottom/left wrist diagonally: 陸 (riku, six)
    • Hidarinagi (左薙, Left Mower) Aimed at left arm's center from the side: 漆 (shitsu, seven)
    • Kesagiri (袈裟切り, Kasaya Cutter) Aimed at left shoulder diagonally: 捌 (hatsu, eight)
    • Tsuki/Shitotsu (刺突, Thrusting/Thorn Stab) Aimed at center of chest, at breastbone: 玖 (kyū, nine)
• Hiten Mugen Zan (飛天無限斬, Flying Heaven Infinity Slash) - An ancient and nearly impossible move made famous by the original Hiko Seijūrō, Hiten Mugen Zan is an extremely powerful shinsoku (GodSpeed) charge which delivers a multitude of sword slashes so fast the naked eye could not possibly count the number of slashes. It is not confirmed, but the Hiten Mugen Zan is in all likelihood the technique that evolved into the Kuzu-Ryu-Sen (Nine Headed Dragon Flash).

• Sōryūsen (双龍閃, Twin Dragon Flash) - Seemingly a simple Battōjutsu strike, Sōryūsen is the first of Hiten Mitsurugi-ryū's two-step Battōjutsu moves. After the first strike with the quickened sword, the user wields the empty sheath along the same path as a blunt weapon. After the sword strike lands, the sheath strike delivers a pulverizing blow capable of crushing bone and shattering wood, but if the sword strike misses, the sheath strike acts as powerful insurance, preventing an opponent's attack and delivering a crushing blow when it's least expected. This move is first seen being used by Kenshin against Udō Jin-e.
  • Sōryūsen ● Ikazuchi (双龍閃・雷, Twin Dragon Flash: Thunder) - An alternate form of Sōryūsen wherein the sword is wielded while still inside the sheath. The first strike is made with the sheathed sword and, once it makes contact, the sword is drawn using Battōjutsu for a second strike. While the original Sōryūsen is designed to make two strikes, Sōryūsen Ikazuchi appears designed with the assumption that the first strike will be blocked. This move is first seen being used by Hiko Seijūrō XIII against Himura Kenshin.
• Hiryūsen (飛龍閃, Flying Dragon Flash) - After assuming a Battōjutsu stance, one rotates one's body rapidly and then stops, aiming the sheath at one's target. The force shoots the sword's grip out of the sheath like an arrow, allowing one to strike a target outside of one's zone and reach. As a Battōjutsu move and as one that requires one's sword to be shot at the enemy, it can be assumed that accurate aim is required for this move (or else the weapon can easily be lost), and that the sheath can then be used as a melee weapon in a second strike, but the latter is not seen. Hiryūsen is first seen being used by Kenshin against Isurugi Raijūta.
• Ryūmeisen (龍鳴閃, Dragon Howl Flash) - An unusual technique in which one uses the godspeed of Battōjutsu to sheathe the sword rather than to draw it in a practice known as Shinsoku Nōtōjutsu (神速納刀術, Godspeed Reaping Blade Technique). The speed and force creates a miniature sonic boom that can be used to temporarily stun opponents with particularly sensitive or acute hearing by affecting their auditory nerves. This move is only seen once, used by Kenshin against Yukishiro Enishi. While this attack would normally only deafen the target for a while, due to Enishi's unusually sensitive nervous system, Ryūmeisen managed to affect his equilibrium as well.
• Amakakeru Ryū no Hirameki (天翔龍閃, 天翔龍の閃 or 天翔龍之閃; Flash of the Heavenly Soaring Dragon) - The secret ultimate technique AKA the ōgi (奥義, secret technique) of Hiten Mitsurugi-ryū, Amakakeru Ryū no Hirameki is a powerful Battōjutsu technique whose secret lies in discovering both the significance and insignificance of one's life, the penultimate requirement needed to master the Hiten Mitsurugi-ryū.

Though its form is that of any other Battōjutsu strike, the Amakakeru Ryū no Hirameki differs in that - while a normal strike is performed by drawing the katana from its sheath on one side while stepping forward with the opposite foot, using a single step - However, this strike adds yet another step (a second step) mid-draw with the foot adjacent to the sheath (creating a Stutter-Step) which momentarily creates an instantaneous acceleration to the forward-charge as well as the sword draw. Meanwhile, the range of the attack is increased and the Timing of the attack changes slightly, which can throw off the opponent.

Although truly, a super-sword attack, it endangers the user by possibly putting the adjacent leg into the free sword's path and draws one even closer to an opponent's sword than usual, but on the other hand, boosts the Speed of the sword draw to beyond-Godspeed and even greater is the boost in force of the strike. By realizing one's insignificance and risking life and limb to protect something else while, at the same time, taking one's own, fragile human life into consideration, the user is able to step into the small margin behind one's own drawn sword and in front of the sword of one's opponent without fail, delivering a beyond-godspeed blow of monstrous power. Additionally, like other Battōjutsu moves of Hiten Mitsurugi-ryū, Amakakeru Ryū no Hirameki is a two-step move and, if its secret should be anticipated and the strike itself blocked or dodged, the second step comes immediately into effect. The immense force of the enhanced draw cuts the air in front of it and creates a powerful vacuum in its wake as the deflected air rushes back into place. Any opponent to deflect or dodge the first swing will automatically be subject to this vacuum and inexorably pulled closer to the user, all the while this vacuum creates intense winds powerful enough to overwhelm and catch their opponents off balance. With the great amount of force being applied to the Amakakeru Ryū no Hirameki, a missed swing leads naturally into an accelerated spin of such centripetal force akin to the Ryūkansen. The added momentum of the spin in addition to the pulling force of the vacuum on both side results in a second strike that greatly dwarfs the first in power. This is best explained to Kaoru by Hiko Seijūrō XIII: "Even if you avoid the fangs of the flying dragon the gusting winds strip away freedom of movement and the claws would rip you apart".

Although the Amakakeru Ryū no Hirameki is one of the most powerful and profound attacks of the series, to learn such a technique is not without its weaknesses, cost and consequence. Those who learn the ways of Hiten Mitsurugi-ryū, and walks its path long enough to learn this technique, must undergo a final test, to be pitted against their master's unrestrained Kuzuryūsen, placing them in a true life or death situation. Faced with life or death, the student must perform the Amakakeru Ryū no Hirameki without flaw, being the only attack in the repertoire of Hiten Mitsurugi that surpasses the Kuzuryūsen in speed and execution- else the apprentice fails and is ultimately slain for naught. Should they succeed, they will have mastered both this technique, and how it is testament, the entire style of Hiten Mitsurugi itself, but at the cost of the preceding master's life.

While the attack is incredibly powerful and seemingly undefeatable, the basis of Amakakeru Ryū no Hirameki, the fighter's will to live and compassion for others allowing them to stand on the edge of life or death, must be strong, free, and unwavering of any doubt and turmoil that lies in the heart of the user. This state of mind is the only condition that will allow the Amakakeru Ryū no Hirameki to be executed flawlessly and guarantee their victory, as being out of this state only allows the user to execute lesser and flawed versions of the ultimate technique (as is the case when Kenshin faces Yukishiro Enishi and his Amakakeru Ryū no Hirameki fails for the first and only time against the Watōjutsu ougi Kufuku Zettousei).

The Amakakeru Ryū no Hirameki is first seen being used by Kenshin against Hiko Seijūrō XIII, and his master is the only known master in the school's history to have survived the final trial. Its second strike is first seen being used by Kenshin against Shishio Makoto. Yukishiro Enishi is the only other opponent who has faced this technique twice.