The Fūma clan was rumored to have been around since the 10th century and specialized in horseback guerrilla warfare and naval espionage, and Kotarō himself often hired and employed bandits, thieves and pirates for his schemes. They were known for their greed, and would supposedly do anything for the right price. He served the wealthy Hojo clan along with his 200 Rappa (Battle Disrupters), using them to create chaos and confusion among their enemies. However, in 1590, Odawara Castle fell after a long siege, and the Fuuma clan was soon disbanded.
Kotaro and the survivors turned to a life of theft, and rumor has it that in 1596 he managed to lure Hattori Hanzo into a trap where he defeated him by setting his boat aflame. However, in 1603, Kotaro's days of plunder and robbery came to an end, as he was captured by an old rival, the Takeda shinobi Kosaka Jinnai and beheaded by the shogunate.
Kotarō Fūma is likely one of the most charming and mysterious characters from feudal Japan. He was said to be 216 cm tall and inhumanly strong. Others said that he was the son of an ogre, or that his eyes were inverted.
In modern fiction Kotarō Fūma tends to be depicted as a flamboyant, demonic-looking ninja, with a penchant for chaos and often associated with the wind. Long red hair is also a common feature. The infamous Fuuma Shuriken is named after his clan, though there's no proof that he actually used such a weapon (not that this actually stops the depictions).
Portrayals in fiction:
- In Lupin III, the Fuuma clan appear as villains, often targetting Goemon. In the Lupin III (Green Jacket) series, they're led by a woman named Shinobu. In the movie The Fuma Conspiracy, they're led by a guy with a nunchaku staff. For the TV special, Lupin III: The Last Job, they're revealed as Italian. (Inverted Trope of McNinja!). Also the ninja dog of Asuka is named Kotarou.
- Yaiba fought Kotaro Fuuma, who was revived by Onimaru along with other warriors. He is depicted as a very tall and muscular man with improbable hair, Badass Beard and a whole arsenal of ninja Elemental Powers and Stock Ninja Weaponry. And to really drive the point home, he can also turn into a hawk-man, making his surname (Fuuma means Wind Demon) even more meaningful.
- A Fuuma clan is mentioned in Naruto, but no Kotaro look-alikes are seen. The oversized shuriken used by Sasuke are named after the Fuuma clan.
- In Samurai Deeper Kyo the member of the Twelve Divine Generals Makora is actually Fuuma no Kotarou, Sasuke's friend and, essentially, an Artificial Human with shadow-manipulating powers who wants revenge against Sasuke for apparently betraying him. Here he's portrayed by Akio Suyama in Japanese.
- In Nabari no Ou, Kotaro Fuuma is one of the main characters, and an ally of the protagonist.
- In Samurai Warriors and Warriors Orochi, Kotaro Fuuma appears as an imposing, creepy shinobi obsessed with chaos and conflict, capable of stretching his arms like rubber tentacles. He's also the archnemesis of Hanzo. By the third game, he tones down his craziness because of the inclusion of Hojo Ujiyasu (and Kai), his boss, but he still remains a creepy ninja.
- In Sengoku Basara, Kotaro is a silent masked mercenary and Living Legend who fights with two shortswords and a giant shuriken, possessing incredible speed. Though he's rumoured to have demonic heritage, and is ruthless on the job, he's less evil than other depictions.
- A young Kotaro appears in Onimusha 2: Samurai's Destiny as an ally and occasional playable character. He's cheerful and he loves exotic and rare gifts, but is distrustful of women, as he was abandoned by his mother as a child and raised by the women of his village.
- In Persona 2, Kotaro Fuuma is one of the summonable Persona.
- In World Heroes, Kotaro Fuuma (as just Fuuma) is a playable character and main rival of Hanzo, serving as the 'Ken' position of the game to Hanzo's 'Ryu'. He's a brash and fiery ninja. He also is one of the World Heroes representatives in NeoGeo Battle Coliseum
- In Laughing Under the Clouds the Fuuma clan are the main antagonists of the series, and their leader is named Fuuma Kotaro, though it's just a descendant (whether real or just in name is never clarified) of the original historical figure, as the story is set in the Meiji Era.
- Fuuma, The Leader for the New Hanzou Academy students from Senran Kagura series is stated to be a descendant of Fuuma Kotaro. She herself is a good shinobi and her family is historically been righteous and good, rather than villainous as most depictions make the Fuuma Clan be. She herself is a redhead like most depictions of Fuuma Kotaro and uses a Fuuma Shuriken connected to a chain.
- Shall We Date?? Ninja Love depicts Kotaro is a reserved, quiet, and serious young man with Mystical White Hair. He uses wind powers in keeping with the popular legend, but also uses a rifle and is an able sharpshooter.
- One of the bosses in Fire Emblem Fates is a ninja named Kotaro. He's the ruler of Mokushu (Fuuma in the Japanese version), and an enemy no matter which path you take, as he's trying to play both sides to make his country powerful. He's also the one who killed Kaze and Saizo's father (but only Saizo knows this as he kept it secret from his brother), making it personal for the latter. Fittingly enough, killing him as Saizo makes his death a karmic one.
- Kotaro shows up as a summonable Assassin-class Servant in Fate/Grand Order. He's noted to have both foreigner and oni blood because of his clan's attempts at eugenics to create the perfect shinobi. He's generally a good guy and can be very Adorkable at times (his reaction to meeting Sakata Kintoki is to get some pen and paper to get an autograph and show off his ninja techniques).
- In Fate/Extra Last Encore, Kotaro has a cameo in a flashback as an Assassin-class Servant with an unnamed female Master. He and his Master quickly get killed by Robin Hood and his Master Dan Blackmore.