The anime and manga series Ikki Tousen features a wide and diverse cast of characters created by Yūji Shiozaki. The characters as well as their names are loosely based upon the characters from the Chinese novel Romance of the Three Kingdoms. For example, the character Hakufu Sonsaku is based on the historical figure Sun Ce (Sonsaku being the Japanese name for Sun Ce, Hakufu being the Japanese pronunciation for his courtesy name Bofu). The series revolves around Hakufu Sonsaku, a female fighter who attends Nanyo Academy with her male cousin Koukin Shuyu, where seven rival schools fight each other for supremacy in the Kanto region.
Main schools Nanyo Academy is a school named after Nanyang, which based on the Wu Kingdom in the Three Kingdoms period. The top-ranked fighters in Nanyo are known as the , which consists of Shimei Ryomou, Gakushuu, Kouha Kannei, and Genpou Saji. After Kannei's defeat, Koukin Shuuyu becomes one of the Big Four in his place.
The protagonist of Ikki Tousen. A second-year transfer student at Nanyo, she is not terribly bright, but is immeasurably powerful despite being only a D-ranked fighter. Because of her busty physique and high skill, she is known by others as the , and is also known by her predecessor's title, the , due to her fate of conquering all of the rival schools. Hakufu cares little for the politics involved between the fighters, only caring about fighting for the sake of fighting, but is staunchly against unnecessary violence and killing. Lately, however, with trouble brewing all around her, she is beginning to take up the mantle of a leader to protect her friends and family.
Hakufu possesses a unique gift for predicting an enemy's moves very accurately by reading the flow of chi around her opponents, which occasionally makes her seem brighter than she is. For instance, she will put an end to a fight simply by stating the next moves of an opponent with frightening accuracy, breaking his will to fight after he realizes the futility of fighting her. She is also very good at "delayed striking", where she makes a feint attack in order to leave an invisible "chi bomb" which detonates moments later while the enemy's guard is down. She is skilled at "inner striking," which is another chi attack where she sends her chi into a person, causing damage to manifest at unusual places. She also inherited Master Chosho's knowledge of chi magic, and, while currently unaware of this, is able to use it partially by instinct. Chosho passed it to her spiritually while Hakufu was unconscious; this is how she healed Koukin after she stabbed him; she slept with Koukin and extracted the evil chi from his body into her own (an uncommon method). She still has the evil chi contained inside her, and it appears on her body as a skull-like mark and is slowly creeping up to her heart.
Hakufu harbors a powerful dragon as one of the Three Great Rulers (the founders of the Three Kingdoms, along with Sousou and Ryubi). Before joining Nanyo, Hakufu lived with her mother, Goei, outside of Kanto where she, like the samurai, practiced things like flower arrangement and the tea ceremony while training heavily in martial arts. Goei was hoping to spare Hakufu her fate, but after Hakufu pummeled a traveling fighter looking for easy prey, they moved in with Koukin. She is very girlish and happy-go-lucky but is capable of wisdom despite having very bad luck. For instance, in one scene where she is just about to deliver a finishing blow to Kannei, her panties get caught on a branch, tripping her over. Nanyo has officially declared Hakufu to be their ruler. She learned the Water Dragon Fist attack from Choukou with the help of Rikuson and Saji, but has apparently killed Saji who was under the guise of Ouin. After Saji's death, she has become more "leader-like", though her airheaded nature still shows.
Hakufu's anime incarnation portrays her as a low ranked and low skilled fighter, and has demonstrated none of her unique fighting gifts or chi powers and is arguably more stupid. In addition to her stupidity, she is more prone to doing dumber things, and either does not mind or is unaware of people harassing or hitting on her. She relies heavily on her dragon or her personal skill alone, and even when possessed by her dragon, she is easily stopped by the other main characters she fights before any damage can be dealt, as opposed to her manga counterpart which is extremely difficult to stop and required the aid of artifacts. She also does not inherit Master Chosho's chi magic (who does not exist in the anime); instead, she undergoes training with Ukitsu's master Chokou. She is possessed by Totaku at the end of the first season but is saved by her dragon who devours him.
In Ikki Tousen: Dragon Destiny, her role is reduced to a minor character, but became a major player in the Battle of Red Cliffs. She was not portrayed to be as idiotic as the first season, and is actually more of a ditzy character than an idiot. Upset at being the cause for much of the violence in Kanto, she traveled to Kyosho to challenge Sousou to a duel in order to end the conflict. She had to take on Kanu instead, who took Sousou's place, and during the fight, Hakufu became possessed by her dragon. Sousou appeared while in full control of his own dragon and dealt a powerful blow that sent Hakufu flying out of the area, leaving all three schools to think she was killed. Her unconscious body was discovered in a lake by Hakugen, who brings her to Chokou. He performed a revival on Hakufu's body but was only able to wake her dragon. Ukitsu gave her life in order to revive Hakufu's soul. Hakufu thus recovered and gained complete control of her dragon. She returned at the Battle of Chibi to fight Sousou, where she and Ryuubi teamed up and defeated Sousou. At the end of the series, Hakufu and Ryomou now work at a cosplay cafe, dressed as cat maids, and hopes to use the money to go on a "battle tour" around the world. She returns as a main character in Great Guardians, and is able to resist Genpou Saji's (the "real" Saji) genjutsu.
Ryomou is a third-year student at Nanyo Academy. She is an odd girl with short blue hair and green eyes, a distinctive beauty mark on her left cheek, and a very strange history, mainly tied to her mysterious left-eye patch, and is always seen wearing fingerless gloves and combat boots. Powerful and a B-rank, she is also one of Nanyo's Big Four. She has a habit of wearing a blue miniskirted French maid outfit, and specializes in submission wrestling moves, throws, and joint attacks which she uses in conjunction with a pair of handcuffs she carries, and is also very proficient in making chi blasts. Her earlier life before she became a fighter is unknown, but is hinted as being tragic and painful. She, Teifu, and Saji have been best friends long before the start of the series, and Ryomou is in love with Saji and cares for Teifu (who loves her). Ryomou has always fought for the fun of it, and considers herself no one's woman. Presumably because of her dragon, she has a minor split personality; one is fairly shy and normal and the other is psychosexual. Her psycho side is not nearly as bad as Ryubi, Sousou and Hakufu.
Three years prior to the start of the series, Ryomou fought Ryuubi when her dragon had awakened, and saved her life right before Ryuubi attempted to rip her own heart out. In the process, Ryuubi's dragon possessed Ryomou's left eye, and now perfectly coexists with her. Its power even healed her completely after being mortally wounded and stabbed through the heart by Teni. No other characters seem to be in harmony with their dragons as much as Ryomou, but she still seals it with her eye-patch and is believed to be dying because of it. Very few are aware of this, and it is not stated whether she shares Ryuubi's dragon or now has her own. While she has it, she is as powerful as the other Three Rulers. Her magical eye may be a reference to the Chinese idiom "To look at a person with a new eye," or reevaluate them or not to judge them by their appearance, an idiom attributed to Lu Meng who was as brilliant a scholar as he was a warrior.
In the anime series, Ryomou is much more taciturn and serious than her manga counterpart to the point of being almost unemotional, and is not shy or spoony and acts uninterested in relationships (in one scene, she is not even phased when Saji puts his hand down her shirt and gropes her). Her magatama is also shown as being silver in the first season, and by the second season she is arguably as strong as Kakouen, though she retreats during their first battle in order to protect the Dragon Jade. She does not have a past relationship to Seito and Ryuubi either, instead her dragon appears to be her own, though how she got it remains unknown. She also appears to be closer to Hakufu than she does in the manga, and goes out of her way to help the Nanyo leader whenever she can; in Dragon Destiny, she even went out on her own to find the Dragon Jade to save Hakufu. She was badly injured after being ambushed by Teni until Chouun came to her rescue, but Ryomou awakened her own dragon, defeating Teni. Choun was able to knock out Ryomou, bandage her, and return her to Nanyo after stealing the Dragon Jade. Choun stated that if Ryomou had not been injured during the awakening of her dragon, Ryomou might have been able to defeat her. Ryomou recovered to full strength and played a part in the Battle of Red Cliffs, defeating Kakouen. She is now working along with Hakufu in a cosplay cafe, dressed as a cat-eared maid and wearing a heart-shaped eye-patch, though she and Hakufu lost that job and numerous others in Great Guardians because of Ryomou's clumsiness and beating on customers. Ryomou's dragon, unlike Hakufu's, did not go back into hibernation after Red Cliffs, and it is revealed to be killing her.
Hakufu's rich cousin and a second-year student at Nanyo Academy. He is an attractive pretty boy, as both Kanu (Tokyopop translation only) and Ukitsu have expressed exclusive interest in him (this trait was toned down in the anime). Although only a C-ranked fighter, his lack of confidence and his short resume of victories (or battles for that matter) keep him from becoming A-ranked despite already having the power of one. He has a crush on his cousin Hakufu and is generally shy and well-meaning, making life very difficult for him. Oddly, Hakufu does not seem to mind being naked around him, which shows how much she is really connected with him, but at times she thinks he is a pervert whenever he is caught in an embarrassing situation (such as Hakufu catching him staring at her things). He is now one of Nanyo's Big Four, taking Kannei's place after he was defeated.
Koukin has demonstrated some great power when he defended Hakufu and Kakouton from the Ugan gang, which astonished even Kakouton. He stayed behind to fight and eventually was captured, allowing the other two to escape. While being held captive in Kyosho, he was seduced by three beautiful girls (one of them being Seito's spy, Shokan, who reveals her identity to him afterwards) in an attempt to make Koukin betray Nanyo and fight for Sousou. This is, in fact, part of the plan for the Battle of Red Cliffs; with Koukin personally enacting "the plan of bodily harm." Once the Kyosho forces are scattered in the battle he breaks free, easily defeating Kaku and Gakushin. He is currently trying to locate the separated Nanyo and Seito forces in order to take command, as per his fate in the battle.