Chifuyu Orimura is a character from the Infinite Stratos anime and light novels.
Chifuyu is Ichika's older sister, and currently his Homeroom Teacher in Class One, as well as the 1st Year Dorm Supervisor in the IS Academy. She is the former IS Representative of Japan and a Mondo Grosso champion before she retired. Additionally, she is a close friend to the IScreator, Tabane Shinonono.
In the AWA fics, Chifuyu serves as one of the many instructors in the AWA Academy.
In the XP4 fics, Chifuyu is an instructor on both Heroes Coalitions and Vanguard Academy.
She is a tall woman (thus shorter than her younger brother) who has long black hair, which is split into parts in a similar manner to Ichika's. She's also said to possess good fashion sense and the way she carries herself is seen as being regal, like a high-borne lady. Her normal IS teaching outfit consists of a formal white shirt, with a black business overcoat and matching skirt, green tie, stockings and high heeled shoes. For IS Training, she would change into a white jogging suit.
In the light novel and reboot manga, other characters have often said that she has a very good figure, having a slender voluptuous body without any trace of fat on her, and is compared to a model by her "worshippers" on a regular basis. Even Ichika tends to get a little embarrassed when he sees her in clothing that accentuates her figure, such as the black bikini she wore to the beach.
She is seen to be very stern and strict, even to her own family, as seen when she tells Ichika to call her Orimura-sensei instead of his more familiar Chifuyu-nee ('Big Sis Chifuyu'). She is also very prideful and stoic, having cared for Ichika since they were young and therefore forced to essentially be a parent to him. Also, being a very skilled IS instructor, Chifuyu has stated that what makes her strong is her little brother Ichika, for it is him who gives her strength. She has a following of many girls that admire her, being the first Mondo Grosso champion, and call her things like Onee-sama (very respectful 'Big Sister') as well as hang onto her every word. Chifuyu thinks how amazing that it seems "all of the idiots have come to her class" (referring to her students). In one way or another, Chifuyu also gets particularly annoyed whenever the girls start making disturbances inside the school, especially if such cases would involve Ichika.
Despite her strictness, it seems she also has a far more casual side, that of a normal woman who enjoys drinking alcohol (which apparently even Laura Bodewig does not know of, despite having trained under her for a full year), and messing with her juniors. She acts very differently at home, which is why Ichika was caught off guard so much the first day, as she doesn't do much housework, leaving Ichika to tend to things. She also does like to tease others on occasion, especially Ichika, who is very susceptible to her. She is also very protective of Ichika, as he's the only family left after their parents abandoned them. She was the one to enroll him into the I.S. Academy almost immediately after it was confirmed that he had the ability to pilot the female-exclusive IS units. Some of the characters noted that her closeness with him seems a little suggestive which only serves to incur a bit of her wrath when they tease her about it.
More so, the girls noted that the interaction between her and Ichika during certain situations, such as Ichika was seen blushing profusely after seeing his own sister in a rather revealing black two-piece swimsuit, however this could simply be because he was embarrassed of seeing her dressed in a swimsuit. There was also their initial impression on the massage incident, but that was just the girls jumping to conclusions. Through this, Chifuyu is highly aware that Houki, Cecilia, Charlotte, Rin and Laura are in love with her younger brother Ichika.
In battle, Chifuyu is very level headed and even relaxes as she would smile and mock her opponent. This confidence seems to come from her former title as world strongest. She didn't even show any worry or fear about facing an IS without one. As well, despite having allowed the personal IS student to fight in real battles, she deeply regretted that she had; accepting that it was an unforgivable action for a teacher and adult.
She is known worldwide as the first generation pilot who won the first Mondo Grosso, thus obtaining the title of "Brunhilde" and the 2nd place finalist of the second, which only happen because she forfeited her match in order to save her younger brother. Her skills are considered the best in the world in that she had to go against the other IS representative candidatesof various countries while wielding only one weapon - the Yukihira. Unknown to world, she was the pilot of the very first IS, "Shirokishi" (The "White Knight" of the "White Knight Incident") and then later the "Kurezakura", which she used in the Mondo Grosso. Her Kurezakura is currently unusable because of a incident that happen sometime between the second Mondo Grosso and the start of the series.
She is a master of kendo, kenjitsu and various other martial arts, as in the past she taught Ichika how to wield a real katana, among other skills. An example of her skills was when she came between Ichika and Laura, wielding a katana sized for the Uchigane IS against Laura's beam saber. Ichika has noted that her skills in kendo are greater than Houki Shinonono, who won kendo tournaments at the national level.
She also shows a great attention to detail in IS combat, as shown when she was giving Ichika (and later Cecilia) a lecture on their flaws, wearing them out in the process. This allows her to correctly predict what could happen and prepare for it. In Volume 8, knowing countries would want not only the IS cores from the Golems lll but also the Byakushiki, she send Ichika out that day to prevent that.
Both Tabane and Ichika state that she was the previous pilot of a first generation IS and was once the wielder of the weapon Yukihira (which is now used by Byakushiki). She was made a legend due to its unique characteristics and also since it was the only weapon she wielded during the Mondo Grosso.
Her physical attiributes are unparalleled, which was demonstrated when she fought an American IS in Volume 8 with nothing but a few katana (although she couldn't damage the pilot). Tabane has stated that even her genetically enhanced body is only slightly superior to Chifuyu's natural physical abilities. She's posses great strength, speed, flexibly, dexterity and agility that allow her to be a dangerous opponent for even a IS pilot. She also uses this against Chloe Chronicle to fend off the smaller girl's attack that utilized very high technology to induce a virtual bubble around her. She admitted that she's not a normal human.
- Chifuyu's name in kanji means a thousand (Chi) winters (fuyu). Thinking of it, her name matches her cold personality. It also has the exact opposite meaning as her brother's name.
- She also seems to be able to read Ichika's mind at select moments. This most likely come the fact that she`s raised him his whole life and knows better than everybody else.
- Chifuyu's seiyu, Megumi Toyoguchi, portrayed certain well-known superiors to the protagonists who are portrayed by Koki Uchiyama. Such as Aqua and Ventus in Kingdom Hearts Birth By Sleep, Mihiro Oiwakken and Banahger Links in Mobile Suit Gundam Unicorn. Sara Valestein and Rean Schwarzer in The Legend of Heroes: Trails of Cold Steel.
- Both of IS's Chifuyu used had knight theme's, first a white one (White Knight) and later a black one (Kurezakura) Both of her young siblings would inherited these traits with their personal IS; Ichika's Byakushiki based after the White Knight IS, while Madoka Kurokishi is likely based after Kurezakura.