Ryu Kumon

Kumon Ryu (リュウ) is a wandering martial artist and master of the Yamasen-ken. "Kumon" is translated as "Anguish", whereas the existing name "Ryuu" means "Dragon", thus his name seems to mean Anguish Dragon, which is fitting given his extremely hard life, and hardened stoic character.

Story
Ryu is a wandering martial artist and expert of the Yamasenken. When he was 6 years old, he and his father were a very poor family that owned the shoddy Kumon Dojo. One day Ryu's father had an encounter with Genma Saotome. After Genma found out about the Kumons' financial problems, he gave Ryu's father a scroll containing the techniques of the deadly secret art of Yamasenken, a.k.a. Fist of One Thousand Mountains. This led Ryu's father to believe he could use the Yamasenken to restore his dojo, but when he practiced its attacks indoors he ended up destroying the building, causing it to fall on top of him which led to his death. With his last moments of life, he gave Ryu the scroll and told him to find the scroll containing the companion Umisenken. Since then Ryu has traveled alone without any family or friends which led to his harsh and untrusting nature.

Ten years later, he comes across Genma's wife Nodoka, when saving her from a rampaging bear, she tells him that he is her long lost son, Ranma, since the scroll he is carrying has Ranma's name written on it. While somewhat surprised by his coincidental good fortune in encountering the wife of Genma, Ryu immediately takes the opportunity to play along, in order to find the Umisenken scroll, and takes up residence within her house. Ranma discovers that Ryu is misleading his mother, and after being beaten and threatened to be exposed if he interfered, decides to learn the deadly Umisenken technique from his father in order to counter Ryu's Yamasenken. Once Ranma mastered the Umisenken, he finally managed to defeat Ryu after a harsh and difficult battle.

After the fight, Genma informed Ryu that the Umisenken & Yamasenken were created for stealing and breaking into peoples houses. He gave it to Ryu's father so that he could steal enough money to be able to afford to rebuild his dojo. After learning this, and being told that even this represented a way to live, while all he was using them for was empty destruction, Ryu was saddened with regret over having wasted all those years in an empty pursuit. He sealed the scroll in a hole covered with dirt together with the Umisenken and (temporarily) Genma himself, possibly forswearing to personally use them as well. Although Ryu knows about Ranma's dual identity, he finally refrained from telling Nodoka, and used his parting words to tell her that Ranma may be closer than she thinks, in order to provide some comfort. He remains fond of Nodoka, and seemingly turned into a nicer person from the combination of her motherly kindness, and the conclusive cathartic revelation.

Personality
Ryu Kumon is a driven, manly, and quite ruthless, martial artist, and was willing to extremes in order to restore his family's dojo, including pretending to be Ranma, attempting to rip the latter's heart out when he was distracted by his mother, threatening to expose the latter if he interfered, and briefly considered torturing Nodoka for information, but couldn't go through with it.

The deaths of his parents, and his harsh lonely life have turned him fierce, cold, militaristic, and independent, seemingly preferring killing to stunning strikes (against the bear and during his initial confrontation with Ranma). Ryoga, and Konatsu, are the only character in the series at least as miserable as himself.

However, his word is his bond, he has a strong chivalrous streak and saved the life of Nodoka without a second thought when he thought that she was an endangered bystander; and he was very touched by, and grateful for, her motherly love, and reevaluated his life after learning the truth of his school. So, much like them, he seemed very positively affected from being treated with consideration.

Unlike most other young male fighters in the series, he is not shy with with attractive young women, and seems quite confident in his ability to charm them. He also mostly lacks the usual goofy quirks, and seems unused to magic oddities.

Fighting Techniques
Ryu practices the Yamasenken (山千拳—Mountain of 1000 Fists, also known as the "Way of the Noisy Thief"), one of two secret and forbidden styles of martial arts that Genma developed when he was younger. This one is based upon brutal 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." Thanks to his unorthodox and ruthless fighting style, Ryu was one of Ranma's most dangerous adversaries, and defeated him twice, though the first time through cheating. It is an incredibly unrestrained and merciless style based on intimidation, incapacitating grappling, and crippling or killing blows, vaguely reminiscent of the pragmatic Krav Maga.

Opening Move: The user shouts something distracting at the opponent, such as "Freeze!" or "Behind you!" This can severely distract opponents or even freeze them in their tracks, making them susceptible to sucker-attacks. The techniques are...

Mōko Kaimon Ha (猛虎開門破—"Fierce-Tiger Opening-Gate Strike"): A powerful kick through the opponent's guard by separating their blocking arms apart. Ryu used this to kill a rampaging bear.

Kaichū Hōju Satsu (懐中宝珠殺—"In-the-Pocket Gemstone Kill"): An arm-locked bear-hug manoeuvre, to force opponents to either surrender or have their backs broken.

Dokuja Tanketsu Shō (毒蛇探穴掌—"Poison-Snake Searching-Hole Palm"): A fierce strike to the chest area, in an attempt to literally rip out an opponent's heart. It knocked out Ranma for several minutes, despite being saved by Genma. However, he was also distracted at the time.

Kinshi Kinbaku Shō (金絲緊縛翔—"Gold-Thread Tightly-Binding Flight"): Ryu throws a rope around his opponent, tying them up.

Geimon Tessen Shi (迎門鉄扇指—"Welcome-Gate Iron-Fan Fingers"): After the former. A powerful pointed strike towards the solar plexus, with all fingers extended. Female Ranma had to limp home in great pain up to an hour or two afterward.

Kijin Raishū Dan (鬼神来襲弾—"Fierce-God Assault Blast"): Spreading arms strikes so powerful that they create vacuum arc projectiles.

Kijin-Gun Dai Ranbu (鬼神群大乱舞—"Group-of-Fierce-Gods, Great Chaotic-Dance"): A strange whirling dance while throwing multitudes of Kijin Rashuu Dans in virtually any direction.

Saidaikyū Kijin Raishū Dan (最大級鬼神来襲弾—"Strongest-Level Fierce-God Assault Blast"): Multiple regular-sized Kijin Raishū Dans sent in the same direction. Making into a powerful attack that is capable of carving a large iron Buddha-statue into pieces, and very painful even for Ranma himself, but not enough to deter him for more than a few seconds. Larger, and more powerful than the basic Kijin Raishu Dan because of the multiple simultaneous strikes.

Other appearances
Despite Ryu being a one time only character in the manga, he did make an appearance in the video game Ranma ½: Battle Renaissance, in which he was voiced by Mitsuru Miyamoto. There was a planned dubbed version where he was voiced by Matt Smith, but it was never released for unknown reasons. '