Musabetsu Kakutō Ryū (無差別格闘流 "School of Indiscriminate Grappling") more commnly known as Anything Goes Martial Arts, is a fictional school of martial arts from the anime and manga series, Ranma 1/2. It is the art used by the main character Ranma Saotome as well as his fiancé Akane Tendo and founded by Happosai.

It is most commonly believed that Musabetsu Kakutō Ryu was founded by martial arts master and pervert lecher extraordinaire Happosai during his travels around Japan and China long before the start of the series. How long ago is rather disputed as his exact age has never been disclosed, in the manga, it is sometimes stated that Happosai is around 100 to 300 years old with his training trip happening when he was still a young man. If this figure is true, then it is safe to assume that the school itself, or at least it's beginnings are quite old. What is known is that sometime before the start of the series, Happosai took two young apprentices, Soun Tendo and Genma Saotome as his students, an act which would lead to both the creaton of the two main branches of Musabetsu Kakutō Ryu, as well as his temporary demise.

After Soun and Genma were able to imprison Happosai in a cave with sake, explosives and a shinto seal, the two went and founded their respective branches of Anything Goes, both anemd after their families. Soun would eventually settle down to teach his Tendo school to his daughter Akane while Genma would later take his son Ranma on a ten year long training journey (wherein both inadvertently get cursed) before presenting him to Soun for the eventual reunification of the two schools.

True to its name, Musabetsu Kakutō Ryu or Anything Goes Martial Arts, is based on learning and adapting many different styles of martial art, taking what works and discarding what doesn't. As such Musabetsu Kakutō Ryu is not confiend to a single way of thinking or philosophy when it comes to martial arts. This give the practitioner of Musabetsu Kakutō Ryu the advantage of adaptability and unpredictability in a fight since he or she would ideally know moves and techniques from many different schools that comliement each other, minimizing perceiveable weaknesses. In this respect, the ideal practitioner of Musabetsu Kakutō Ryu is its heir apparent, Ranma Saotome. Throughout the course of the series, Ranme not only learns multiple styles and techniques from both his friends and enemies, but also displays the uncanny ability to adapt or modify these techniques in mid-battle to catch his oppoenent off-guard.

It is interesting to note that the philosophy of Musabetsu Kakutō Ryu is similar to that of many martial arts used by many real-life mixed-martial artists, most of whom cross-train in many different disciplines to create a balanced, well roudned fighting style.

After Soun Tendo and Genma Saotome sealed Happosai, Musabetsu Kakutō Ryu was divided into two school, the Tendo and Saotome schools. Other than this, Happosai also has his own variation, Ganso Musabetsu Kakutō Ryu (Creative Indiscriminate Martial Arts), sometimes translated as the Founding School of Anything Goes Martial Arts, though the school itself (which relies alot on trickery) seems to have been developed to compensate for Happosai's advanced age.

In general, the Saotome school is the more aerial of the two schools with both Ranma and Genma Saotome performing feats of aerial acrobatics during their fights. In this respect, it is probably the closer of the two schools to the original school of Happosai, since the latter also prefers to go to the air when fighting. The Saotome school is also host to a number of offbeat techniques named after animals, such as the "Crouch of the Wild Tiger" which basically invovles prostating oneself before ones enemies. Diversionary tactics such as the latter are hallmark of the Saotome school, the greatest, most secret technique of the school supposedly being running away against overwhelming odds to regroup.

The school also has two sealed martial arts developed by Genma Saotome, the Yamasenken (Mountain of a 1000 Fists) and Umisenken (Sea of a 1000 Fists). Both are schools designed to help in theivery and have some rather deadly attacks. It was in attempting to learn the Yamasenken that the father of Ryu Kumon ended up killing himself and destroying their dojo, causing the younger Kumon's quest for revenge against the Saotomes.

Training for the Saotome school involves turning everything, even mundane events into training exercises, as well as experimenting with many new techniques (as is the way of Musabetsu Kakutō), however this can lead to some unexpected results.

The Tendo school is generally considered the more ground based school of Musabetsu Kakutō Ryu, this is supported by the fact that neithter Akane or Soun Tendo use aerial techniques. However, it is a mistake to believe that the Tendo school is purely ground based as both Akane and her father have been known to jump significant heights and use aerial attacks when necessary. However, the school is still primarily ground based as shown whenever Soun and Akane spar, or when Akane faced her amourous schoolmates in the morning, early on in the series.

It is also possible that the Tendo school has been taught to more than those who are shown practicing the style in the series. This is due to the fact that Soun Tendo owns the Tendo Dojo and most probably made a living out of teaching.

The Creative Indiscriminate Martial Arts, sometimes translated as the Founding School of Anyting Goes Martial Arts, Ganso Musabetsu Kakutō Ryu is Happosai's variant of Musabetsu Kakutō. This variant mostly involves alot of ki manipulation as well as stealth and trickery. Whether of not this is the original school of Musabetsu Kakutō Ryu, or whether it was developed by Happosai as a response to his advancing age is unknown. It seems different enough from the Tendo and Saotome schools that it can be considered a later development, hwoever, both Tendo and Saotome schools have themselves evolved further with the appropriation of new techniques.

The majority of the Musabetsu Kakuto Ryu techniques shown in the series are either done by Happosai or by Genma or Ranma Saotome. In the case of the Ranma, many of his techniques are actually moves he learned from Cologne, elder of the Chinese Amazons. There is a subset of moves that only Hinako Ninomiya is able to use because of the training Happosai gave her when she was young that allows her to absorb and utilize raw ki from her opponents.

Ranma's training in the Musabetsu Kakuto Ryu began under Genma when he was only six. He is well aware of the poor role model Genma was for him, but has well-learned his father's methods in maximizing his effectiveness. His first ten years of training were classical, focused entirely on his time with Genma, but an encounter with the Chinese Amazons and his subsequent defeat of their champion, Shampoo, soon exposed him to another style of fighting. Since then, Ranma has consistently incorporated techniques from the Chinese Amazon village and other sources into the Musabetsu Kakuto Ryu to create his own unique style that is well-suited to just about any combat situation.

• Saotome Secret Technique: Fast Break: The "secret attack" of the Saotome School, which Genma says is based in the concepts of motion, contemplation, and opposition. In other words, the user runs away from his opponent, buying time to think of a better way to attack. Ranma used this only once, contributing to his victory over Ryoga after the eternaly "lost boy" learned the Breaking Point technique.
• Cat Fist (貓拳—Nekoken): A condition Ranma is subject to when his fear of cats reaches an unbearable level. When this happens, he is nearly invincible, acting like a cat, with swipes of his "paw" that can shred everything around him; however, he is mentally a cat, making catnip a major weakness of this form. He can only be brought out of the Nekoken by triggering his curse or by falling asleep in the lap of someone he trusts deeply, usually Akane.
• Chestnuts Roasting On An Open Fire (火中天津甘栗拳—Kachu Tenshin Amaguriken): a flurry of attacks of blinding speed. It is also known as the "Chestnuts Roasting on an Open Fire" technique due to the method of learning the technique, which develops lightning fast punches such that one can snatch chestnuts from a fire without burning themselves. Because Ranma was affected by the Full-body Cat Tongue pressure point at the time, he could not handle heat. Thus, he does not master this technique in the conventional manner, but instead does so by pulling piranhas from a fish tank at a local fair using his bare hands. Note, however, that in the manga this is not a special attack in the physical sense, but rather a speed exercise. In the anime it is his most used special attack, and it is mentioned that because of this exercise, Ranma can throw 300 punches per second.
• Shiskibob (manga only): An attack Ranma uses to counter Mousse's Takazume Ken (Hawk's Talon attack), basically he uses a rapidly ascending kick to avoid Mousse's attack and slam into his face like a kabob rod going through meat and vegetables.
• Hidden Weapons (Kanuma Emono): Originally, the art practiced by Mousse of the Chinese Amazons. It allows the user to create pockets of folded chi, or voids, on themselves or within their clothing. This allows them to carry many weapons on them; chains, shuriken, kunai, senbon needles, etc. The type of clothing they wear aids them in their art; the more volumous, baggier, the clothing the larger the weapons and amount of storage within them as well. During his Ranma's fight with Mousse, Ranma is able to effectively duplicate this technique although he is far from the level that Mousse has displayed.
• Puppet Grip (manga only): Ranma clings to his opponent's back, then manipulates his/her arms like a puppet. Used it to try and make Kuno eat some Ramen in the Martial Arts Takeout Race. His efforts failed when Kuno exploited the one flaw: the technique doesn't control the victim's head, which means the victim can thwart it by simply keeping his mouth closed.
• Parlay du Foie Gras: The "Parlay" involves quickly stuffing your food in your opponents mouth. Because of this, the user does not have to develop the characteristic distended mouth that many champion "martial arts diners" have; Ranma used this technique to defeat Chardin Piccolet III.
• Heavenly Dragon Blast (飛龍昇天破—Hiryū Shōten Ha): Cologne taught Ranma this ki-based attack where the fighter performs this by becoming a "Soul of Ice" by devoiding themself of emotion. Also then proceeding to get a rise of hot ki from the opponent(s) to get a reaction. When this happens, the user then starts to lead their opponent in the "rasen stepu", or spiral step. Once this is completed, the user pours all of the ki in an upward fist strike that creates a tornado of ki that carries off the opposing fighter(s) in a single blow. It is perhaps the most powerful and versatile technique of all, this secret Amazon technique gives Ranma the edge he needs to defeat his toughest opponents: Happosai, Herb, Saffron, Kirin, and others. It has been shown that the opponent need not radiate hot ki; Ranma can gather excess hot ki in an area (such as from Saffron's heat attacks) to create the whirlwind. A great deal of cold ki can lessen, or even nullify, the effects of the whirlwind. In the manga it is his most used special attack and works on all heat; it has even been successful against Happosai's lust. Ranma has used several variations of the Hiryū Shōten Ha in both the manga and anime, including:
  • Heavenly Dragon Blast Revised: Horizontal Spiral (Hiryū Shōten Ha Kaiteiban: Gedan Rasen): The unique situation offered by Natsume and Kurumi's Hiryū Karimbou attack made this possible. The spiral created from Kurumi's ribbon radiates hot ki; Ranma need only gather the hot ki from the ribbon to create the whirlwind. Since none of the combatants were radiating hot ki, Ranma used the whirlwind to push Akane into her opponents, the flying kick of doom. The side effect was the nullification of Natsume's own ki bolt, being cold ki itself, it would weaken the whirlwind, but, since the hot ki in the spiral is overwhelming, the effects were negligible. (This is the best rationalization that can be made from this alternate and anime-only attack.)
  • Descending Dragon Shot (Hiryū Kourin Dan): Ranma discovered that the Hiryū Shoten Ha is ineffective against Herb, who knows of the attack (and thus managed to change his ki aura in time to lessen the effects of the whirlwind). But, Ranma noticed that excess hot ki gathered up in the sky. He created another whirlwind, allowing Herb to throw him into it. While in the air, Ranma gathered the hot ki and, with his own cold ki, fired himself downward, straight into Herb, for the final attack. It appears quite like a downward Mouko Takabisha, but larger and much more deadly, backed by gravity and ki together.
  • Ice Dragon Breakthrough (Hiryū Hyou Tōppa): This is Ranma's final attack against Saffron in volume 38 of the manga, completed with the aid of the Phoenix people's artifact which produced an icy cold touch based effect. Ranma plans on throwing a whirlwind though a channel of cold air surrounded on both sides by the hot air from Saffron's blasts, and that in the swirl in the middle the whirlwind will become highly concentrated, squeezing the cold spiral into a razor's edge. He is unable to find an opportunity to use the move however. He gets his chance whe Akane throws her frozen doll form at Saffron, tunneling through Saffron's heat and giving a Ranma a small channel of cold air to fire the Hiryū Hyou Tōppa. The refined Hiryū Shoten Ha drills straight through Saffron's chest, defeating him.
  • Heavenly Dragon Searching Blast (Hiryū Gyōten Ha): Also used in volume 38 of the manga. Because Akane is dying, and only the water from the Dragon Faucet can save her, Ranma, falling from the sky, has no time to get Akane to the water. Instead, he channels all his energies into the whirlwind. The whirlwind is forced downward, then curves as it reaches the Dragon Faucet. It breaks the Faucet, causing the Dragon Head to spew the waters into the sky. In this way Ranma saves Akane's life, but also destroys an opportunity to remove his curse.
• Pantyhose Shooting Star Kick (Pansuto Ryusei Kyaku): An extremely powerful kick Ranma uses to defeat the transformed Pantyhose Taro. Using the elasicity of Happosai's bag of pantyhose as a catapult, Ranma focuses his ki and uses the extra momentum to deliver an insanely fast and powerful kick to the giant monster.
• Pride of the Fierce Tiger (猛虎高飛車—Mōko Takabisha): Ki attack created which is based on the emotion of confidence, by and for Ranma. Since he could not get depressed enough to re-create Ryoga's attack, he made this. Ranma can fuel it with any emotion, but his personal choice is that of pride. It was mostly developed as a direct counter to Ryoga's Lion's Roar Shot (獅子咆哮弾—Shishi Hokodan) due to the fact that he could not maintain the level of bleak gloom/depression required for it. In the manga, Ranma is able to create a "Double Moko Takabisha" that fires two equally stong ki blasts.

As the founder of the Musabetsu Kakuto Ryu, Happosai knows the martial arts inside and out. Many of his moves are highly advanced and difficult for a young combatant who lacks the necessary experience. It appears that many of his technques are designed to protect himself from the people he ripped off or the women he spied on.

• Happo Throw: A simple technique that Happosai uses on attacking opponents. He hooks their arm or leg with his pipe, then uses their own momentum to throw them a great distance. He can also do it without the pipe.
• Finger Block: Happosai can use this move to stop huge objects or powerful punches aimed at him with only his index finger. It is unknown if he uses his own strength, channels his ki to stop the attack or if this is a special technique that disables the attack's (or object's) momentum. Either way, it is one of Happosai's best defensive moves.
• Happo-Fire Burst (八宝大華輪 Happo Daikarin): Happosai's ultimate technique, and his favorite. He sealed it away because it damaged a bra—one of his many "silky darlings"—once many years ago, but after Ranma pushed him too far he rediscovered his long lost technique. In reality it is just throwing large fireworks at people. They are infused with ki, however, and can cause massive damage. Happosai can also create these bombs in different sizes—some even as big as a small house—to increase their power.
• Battle Aura: as the grandmaster of Anything Goes Martial Arts, Happosai is exceptionally skilled at manipulating his battle aura. In his first appearance in the manga and anime, he uses it to paralyze Ranma with terror. In the anime, he is shown to fire it as a serpentine blast resembling a demonic Chinese Dragon. Several times in both the anime and the manga, he uses this technique to transform into a giant version of himself, and he can keep this up for quite a long time. In the anime, Genma and Soun are also shown to be capable of doing this, but they are not as durable.
• Happo-Mold Burst: a modification of the Happo-Fire Burst used only in the anime, where Happosai's bombs create clouds of paralytic mold instead of explosions. This mold grosses out and immobilizes his opponents.
• Silky Storm: A distraction technique that involves Happosai spinning his pipe and creating a blizzard of bras/panties to cover his escape.
• Extra-Dimensional Warp: Using his Ki, Happosai becomes invisible, the only downside is he can't attack without becoming visible. Used primarily to spy on girls.
• Beanjam Blowout (Anime only): Using his Ki, Happosai creates a large blast of wind to blow his enemies away. This move is named as he created to steal Beanjam from Soun and Genma.
• Fist of the Hermit Crab: Happosai throws several buckets into the air towards his target, then uses his extra-dimensional warp to hide in one. Afterwards he attacks from his bucket as he bypasses his target. In the manga, this technique is part of an entire sub-discipline of the Anything Goes School known as Bathhouse-Fu. He probably devised it to protect himself from the girls he peeped on in public baths.
• Ultimate Weakness Moxibustion: A stolen technique. By burning a mark in a certain spot on his opponent's body, he reduces their strength to that of a baby, reversible only with a counter-moxibustion on another point. Happosai used this on Ranma after the pigtailed youth stopped him on one of his panty raids.

Along with Soun Tendo, Genma trained directly under Happosai. Although much of their lessons consisted of panty raids and working to pay off the master's debts, it is clear that he did learn a lot of his moves from the old pervert. Genma personally trained Ranma from birth using a series of questionable methods and is also responsible for his son's Jusenkyo curse. Shortly after concluding his training with Happosai, he invented two martial arts of his own. He designed them to aid in the thievery he conducted, apparently to fund his training with Ranma, but sealed away his knowledge of both of them after a fellow martial artist killed himself by practicing one of them and bringing down his dojo on top of himself. While much of Genma's skill has eroded with time and cowardice, he remains a formidable fighter.

• The Ultimate Skill of the Saotome School of Anything Goes Martial Arts: The Crouch of the Wild Tiger: This groveling technique is accompishled by first crouching, placing both palms on the ground, and then bowing and scraping for forgiveness. Genma says it is "named for the legendary wild tiger that fell from a cliff and..." but is cut off by a blow to the head from Ukyo. He taught Ranma this before apologising to Happosai for angering the old master. The video-game Ranma 1/2: Battle Renaissance shows a variation where Genma pounces on his opponent after he or she is lulled into a false sense of security.
• Jigoku no Yurikago (Japanese for 'Cradle from Hell'): Genma's only remaining move that is still able to beat Ranma, a powerful grappling attack reminiscent of a parent embracing their infant child. It's so effective in part because it freaks out Ranma. Genma practiced this move by playing with a tire in panda form.

• Yamasenken: One of two secret and forbidden styles of martial arts that Genma developed when he was younger. This one is based upon burglary, specifically the movements and techniques of a noisy bandit who smashes through the front door of a house. Canon translates this style as "Noisy Thief" or "Mountain of 1000 Fists." Genma taught this set to Ryu Kumon's father years ago, which indirectly led to the poor man's death. Ryu now utilizes these moves as well.
  • Opening Move: the user shouts something distracting at the opponent, such as "Freeze" or "Behind you." This stops the opponent in their tracks. The techniques are...
    • Dokuja Tanketsu Shou (Japanese for 'Poisonous Serpent Searching Hole Palm'): Fierce open palm snake strike to the chest area.
    • Kinshi Kinbakusho (Japanese for 'Gold Thread Tightly Binding Flight'): Throw a rope around your opponent, then tie them up with it.
    • Geimon Tetsu Sen Shi (Japanese for 'Welcome Arch Iron-ribbed Fan Finger'): After "Kinshi Kinbakusho", an open palm strike to the throat.
    • Kaichü Houju Satsu (Japanese for 'Jewel Held in One's Pocket Kill'): Armlocked Bearhug submission maneuver while holding one arm behind the back.
    • Mouko Kaimon Ha (Japanese for 'Fierce Tiger Opening Gate Defeat'): Deliver a powerful kick through the opponent's guard by separating their arms.
    • Kijin Raishu Dan (Japanese for 'Fierce God Assault Shot'): Spreading arm strike so powerful it creates vacuum arc projectiles that tear into anything.
    • Kijin Gun-Dai Ran Bu (Japanese for 'Group of Gods Great Boisterous Dance'): Perform a strange whirling dance as one throws multitudes of Kijin Rashuu Dans in every direction.
    • Sai Dai Kyuu Kijin Raishü Dan (Japanese for 'First-Rate Demon God Assault Bomb'): An extremely powerful Kijin Raishu Dan. Larger, faster, and much more powerful than the basic Kijin Raishu Dan because it's charged with the user's ki.

• Umisenken: The other of a pair of secret and forbidden styles created by Genma. Like the last one, this too is based upon burglary, however, this one is specifically designed upon the movements and techniques of a quiet thief who sneaks in through the back door. Canon translates this style as "Quiet Thief" or "Sea of 1000 Fists." When Ryu arrived to find the scroll for this partner martial art, Genma had no choice but to teach it to his son to end the menace.
  • Opening Move: the user takes a stance like that of a ghost, hands limp in front of their abdomen on slightly bent arms. The user then hides their ki. Once the user moves, they become invisible. The techniques are...
    • Gai Ko Retsu Ga Dan (Japanese for 'Armored Door Furious Fang Dismissal'): Counter a hand attack, like the Geimon Testu Senshi, by biting the opponent's attacking limb.
    • Goshin Dai Ryuusei Fu (Japanese for 'Self-protection Big Falling Star Cloth'): Whirling a star designed cloth around the user's body and vanish from sight.
    • Goshin Ryusei Fu (Japanese for 'Self-protection Falling Star Cloth'): Wrap a star cloth around your opponent's head to blind them and stop their attack.
    • Yasha Tan Kai Hou (Japanese for 'She-Demon Deep Sea Bundle'): After "Goshin Ryusei Fu", place a large bundle of earth into the star cloth, flip over the opponent who is then crushed by the dirt. If one's ki is properly infused in the cloth, it will allow the user to hold an opponent's attack within the cloth, so that it can be unleashed against them.
    • Ri Giyo Hon Shin (Japanese for 'Carp Fish Bodyflip'): Flip out of a hold, then move behind an opponent while wrapping them in the star cloth.
    • Haizan Toukai Tai (Japanese for 'High Mountain Reverse Sea Plight'): After "Ri Gyo Hon Shin", drive one's feet into the back of the opponents legs while pulling down on the cloth.
    • Haku Dato Shin Shou (Japanese for 'White Snake Spitting True Palm'): Slipping under one's opponent while striking along both sides of their back.
    • Shichuu Rakuchi Sei (Japanese for 'Brace Falling Down Strength'): Force one's opponents feet apart, striking their legs, so they drop into a split.

Thanks to Happosai's "training" when she was still a sickly young girl, Hinako is able to both absorb ki from her opponents - by using any object with a circular hole as her focus - as well as shoot it back at them as a charged attack. The consequence of this is that she effectively matures whenever she absorbs ki, only to revert back to her child form when she fires it off. As this condition was caused by hitting a set of pressure points, the only way to prevent Hinako from doing these techniques is to hit another set of pressure points on her body, everyday for at least a month. Unfortunately, these counterpoints are located in places that make anybody who attempts to neutralize her looks like a shameless pervert.

• Happōgoensatsu (Happo Five-Yen Satsu) Hinako uses a five-yen coin to absorb ki that is already manifest, usually an opponents battle aura. With the five-yen coin, Hinako cannot absorb ki from someone who is not emmiting any battle aura.
• Happōgojūensatsu (Happo Fifty-Yen Satsu) Using a larger fifty-yen coin, Hinako can absorb ki even if her opponent doesn't manifest a battle aura. While the fifty-yen coin works on a single opponent, Hinako and also use larger ring-shaped objects, such as a basketball hoop, to drain ki from multiple opponents.
• Happōtsurisengaeshi (Happo No-Yen Coin Return) Hinako releases all of her stored ki in a large blast. While it is quite deadly, this attack can usually only be performed once since it effectively drains all of the ki that Hinako has absorbed. The only time she can possibly throw multiple ki blasts is if she has a source of limitless ki nearby, such as a pair of Siamese Fighting Fish.

• Hiryū Karimbou(Anime only): Used by Natsume & Kurumi Tendo, Kurumi spins her ribbon in a spiral pattern while Natsume sends out a ki bolt that travels along the path created by the spiral.

• Happosai - Grandmaster
• Genma Saotome - Master, Saotome School
• Soun Tendo - Master, Tendo School
• Ranma Saotome - Heir to the Saotome Schoo, Happosai's Heir
• Akane Tendo - Heir to the Tendo School
• Hinako Ninomiya
• Natsume Tendo
• Kurumi Tendo