Ryuubi Gentoku is the leader of Seito Private School. She's recognisable by her green eyes, long brown hair, glasses and her large chest size. She is a seemingly unskilled Toushi in almost all respects in that she possesses poor fighting prowess, she is not particularly intelligent and she herself often shows little care or perhaps little understanding towards being a leader. However she does not believe in fighting to solve matters (although often Seito are left with no choice.) and she is generally quite popular among the other Toushis. She is youngest girl
Ryuubi is not introduced until the first episode of Dragon Destiny. She is a very emotional girl and she is often worrying and frustrating her subordinates (Especially Ekitoku Chouhi) because of her lack of skill and her unmotivated attitude. Ryuubi often expresses a lot more interest in her lifelong hobby; reading, than she does for being a Toushi. Despite her flaws, it is revealed quite early on that Ryuubi possesses a very destructive dragon, after Ryomou Shimei awakens Ryuubi's dragon using the Dragon Jade, Ryuubi goes into a frenzy and she nearly goes as far as attacking her loyal friend and subordinate; Unchou Kan-u. Ryuubi is then restrained in a cell and she is starved in order to calm her from her dragon form.
Ryuubi only starts seriously acting like a leader when Kanu U'nchou is captured by Kyosho. It was Sousou Moutoku's desire to recruit Kanu into his army, just as Sousou desired 1,800 years ago. Ryuubi begins to learn to make important decisions and to give commands properly, it is viewed as so important to Seito that Chou'un Shiryuu actually confronts Kanu (who escapes from Kyosho) and asks her to wait for longer before she returns to Seito, in order for Ryuubi to become independent, and not have to rely completely on Kanu and others helping her all the time. Kanu reluctantly agrees and so she does not return to Seito until the re-enactment of the Battle of Chibi. Ryuubi even goes as far as trying to hold off one of Kyosho's Toushi to protect Shokatsuryou Koumei. She still fights poorly, resorting to mainly trying to defend, however Kanu arrives just in time to save her. Sousou Moutoku then appears and provokes the dragon inside Ryuubi, Ryuubi awakens involutarily, however she cannot control her dragon which makes her dragon much less powerful than Sousou's and so she fights a losing battle. However, Sonsaku Hakufu comes to rescue her, and they use their combined powers of their dragons to defeat Sousou. Seito and Nanyo then declare peace with each other, making the end of series two.
In the end of series two, Ryuubi is shown in her library with a huge amount of books she has read or is going to read, Kanu brings in more books for her to read, still in somewhat disbelief in how much Ryuubi can read. Ryuubi then offers a book to Kanu to read (Ironically, the symbols on the cover stranslate as "Ikki Tousen.") Kanu decides to take her up on the offer.
In Great Guardians Seito is given slightly less spotlight, however they are still relatively involved nonetheless. Presumably Great Guardians starts not too far from where Dragon Destiny left off. Kanu returns from her training and Ryuubi shows an almost overjoyed response to her return, it is here where it is revealed that Kanu has a crush on Ryuubi; their relationship with each other is often their main involvement during the third series in some regard or other. Although Kanu is obviously romantically interested in Ryuubi, Ryuubi often remains completely oblivious and it's usually hinted that Ryuubi does not return Kanu's affections, most likely that Ryuubi is not interested in other girls. As the series progresses, Kanu becomes more desperate to try and start a relationship with Ryuubi, to find out if she actually has a crush on her in the first place or to try and simply win Ryuubi's favour over the other Seito Toushi, what makes Kanu even more desperate however is that Kanu often reveals her worries that Ryuubi likes other Toushi's more than her, in particular she worries about Koumei (Who is also revealed to have a crush on Gentoku). However Ryuubi often feels that Kanu is being too pushy or sometimes even scary, throughout the episodes, Kanu scares or embarrasses Ryuubi on multiple occasions, even though Kanu doesn't really have any bad intentions. After a while Ryuubi begins to become quite frustrated with Kanu, the final incident happens when Ryuubi and Kanu go to a theme park with Ryofu Housen, who is possessed by Genpou Saji. Ryofu deliberately flirts with Ryuubi and makes subtle intimate gestures, she then arrogantly accuses Kanu of being jealous, Kanu then loses her temper with Ryofu, however Ryofu gives Ryuubi the impression Kanu lost her temper for no reason, Ryuubi gets angry at Kanu and tells Kanu that she's tired of Kanu ashaming and embarrassing her. Ryuubi then runs off with Ryofu into a haunted house. Ryofu persuades Ryuubi to go in together, despite the fact that Ryuubi wanted to apologise to Kanu for going too far. Ryofu toys with Ryuubi in the haunted house and lets her get restrained, she uses the opportunity to possess Ryuubi.
At first, Ryuubi's possessor (Saji Genpou) keeps a low profile, slowly possessing Seito's Toushi's one by one. However Kanu notices the strange events and disappearances, as well as Ryuubi's changed attitude herself. Eventually, the only Toushi's left who are not possessed are Kanu, Koumei and Bashoku Youjou. Kanu realises what has happened but she cannot do anything to stop it, even after receiving help from Nanyo they are unable to remove the cause of the possession. Ryuubi eventually is freed from her control when Kanu bravely takes an attack from Ryuubi which nearly kills her, Ryuubi impales Kanu with her bare hand however Kanu braves through the pain, and tells Ryuubi how happy she is to know and to have served her and that her friendship makes her very happy. This restores Ryuubi and she is heartbroken over nearly killing Kanu.
Ryuubi, and Seito, then have a more minor role in Great Guardians as they do not participate in the final battle due to their extensive injuries. In the final episode Ryuubi has a conversation with Kanu where they repair their relationship. Kanu also returns one of Ryuubi's books to her, but Ryuubi tells her to keep it because it was her favourite book and Ryuubi says "I wanted to give my favourite book to my favourite person." Thus showing Kanu how much she appreciates her and how much she enjoys being with her, even if she has embarrassed her.
Ryuubi returns in Xtreme Xecutor she still a ditz, yet caring person, but is trying to become a more responsible leader to Seito High School. Ryuubi finds an unconscious Bachou Mouki and takes her to Seito High school to recover.
Ryuubi appears in the manga Ikki Tousen, she also appears in Ikki Tousen: Dragon Destiny, Ikki Tousen: Great Guardians as well as the games Ikki Tousen: Shining Dragon and Ikki Tousen: Eloquent Fist. In the anime Ryuubi has green eyes, large glasses, light brown hair with four orange beads tying the front ends of her hair. She is also known for her big breast that causes some girls to be jealous or want to play with them (Koumei's case).