She joined the Ouran Host Club to pay off a ¥8,000,000 debt after breaking an expensive vase which was for an auction. At first, due to her short hair and androgynous clothes, everyone thinks that she is a feminine-looking/gay boy (apart from Kyoya Ootori, who knew she was a girl from the beginning.) Even after the club found out her true gender, Haruhi still dresses in the male uniform and pretends to be male so she can work off her debt as a host.
Haruhi in "Operation Haruhi and Hikaru’s First Date!" Added by OHSHC-lover Haruhi is, above all, independent and straightforward, and believes that your gender should not define your personality. Since she was raised differently from her classmates at Ouran, she displays more practical, down to earth, responsible qualities and is not easily swayed by the charms of the other hosts. Even when she first meets the hosts, she only reacts nervously instead of becoming immediately infatuated like most of the girls. Haruhi has a deeper voice than other female students, so she is not easily recognized as a girl. Although habitually unflappable, it is shown that she fears thunderstorms (Brontophobia), which terrify her to the point that she is stricken with paralysis. She enjoys peace and quiet, doesn't mind working, and is a fanatic about fancy tuna, which is used as a bribe to get her involved in some of the more peculiar Host Club schemes. Without bribery, Haruhi is described as "apathetic" by the twins when it comes to making some decisions, usually with regard to the host club. Haruhi is sometimes unaware of her own feelings, like her feelings of love for Tamaki in volume 13.
At her old school, she had many friends and was asked out a lot, showing she was somewhat more sociable than at Ouran. Even so, she becomes a popular Host with her regular conversation and charming smile. She often shows her exasperation and distaste for the club, and even her fellow members, but she cares deeply for each of them. They, in turn, love her and regard her very highly, though they don't all put it into words (e.g. Kyoya and Takashi). All six of them are very protective of her.
In her first appearance Haruhi is introduced with a very boyish look: short hair, big glasses, and a baggy outfit. Haruhi has a slender build, causing her body to lack feminine features which is mentioned a few times throughout the series. She has brown hair which she cut shortly after a boy stuck gum in there a few days before school.
Usual Appearance She sometimes has to wear a long wig that resembles how her hair used to be. Clients often comment on her big, shining eyes, saying they give her a more girlish look; the shining is actually caused by her contacts, which the Host Club gave her after realizing that she had some "potential". Throughout the course of the series, many people - girls and boys - grow a crush on her after seeing her charming smile. She resembles her late mother who was a lawyer. She has worn the girl uniforms at Ouran a few times, usually as a disguise. Just before she left to study abroad, she revealed to the school she was infact a girl. The students seemed to have already realized this, but what they thought they realized was that Haruhi was a crossdresser. Haruhi is 155 cm tall (5'1).
Haruhi's first name (ハルヒ, Haruhi) is spelled using the katakana writing system and is a common name given to girls in Japan. It has many meanings depending on the kanji used, but it normally means "Spring Day". Fujioka (藤岡, Fujioka) means "wisteria hill". It can also denote someone who lives near or on Mount Fuji.
- Haruhi's birthday, the 4th of February, is said to be the first day of Spring in Japan. In Japan, the word for "Spring" is "Haru" (春) and is spoken in the same way as the first part of Haruhi's name. Other birthdays that were suggested for her were likewise associated with the changing of the seasons and also floral themes.
- Honey calls her "Haru-chan".
- Tamaki calls her "daughter" and wants her to dress more girly. (So do the twins.)
Haruhi kissed a girl with her first kiss to pay off one-third of her owed debt. Haruhi's mother died when she was 5 years old.
- It was stated that when Haruhi was in middle school, she received confessions of love from boys at least once a month.
- The order in which the Host Club members realized Haruhi was a girl was: Kyoya, Honey, Hikaru & Kaoru, Takashi, then Tamaki.
- The glasses that she wore in chapter one and episode one are her grandfather's glasses.
- Haruhi has the same English voice actress as Winry Rockbell from Fullmetal Alchemist. This creates an amusing coincidence for fans of both series, since Winry is the love interest of the titular Fullmetal Alchemist, Edward Elric - who shares the same English voice actor as Tamaki.
- The Japanese voice actors of Haruhi and Hikaru are married.
- Haruhi uses Ore instead of Watashi. Ore is a method to say 'I' for men.
- Like some of the Ouran characters, she has some characteristics of those from Harry Potter. Therefore, it is shown that she has some characteristics of Hermione Granger: Both are quite intelligent, both are brunettes, and both have friends that are boys. The only differences they both don`t have is that one is British and a wich, while the other is completely mortal and is Japanese, not British.