short for is a Japanese light novel series written by Tsukasa Fushimi, with illustrations provided by Hiro Kanzaki. The story depicts high school student Kyosuke Kosaka who discovers that his standoffish younger sister Kirino is actually an otaku with an extensive collection of moe anime and younger sister–themed eroge she has been collecting in secret. Kyosuke quickly becomes Kirino's confidant for her secret hobby.
ASCII Media Works has published 17 volumes in the series under its Dengeki Bunko imprint from August 2008 to September 2021. A manga adaptation drawn by Sakura Ikeda was serialized in ASCII Media Works' Dengeki G's Magazine between 2009 and 2011. AIC produced a 12-episode anime adaptation in 2010, with four additional episodes streamed online in 2011. A-1 Pictures produced a 13-episode second anime season in 2013 with 3 more episodes streamed online later that year. Bandai Namco Games developed three visual novel video games from 2011 to 2013 for the PlayStation Portable and PlayStation 3 consoles.
Plot Kyosuke Kosaka, a normal 17-year-old high school student living in Chiba, has not gotten along with his younger sister Kirino in years. For longer than he can remember, Kirino has ignored his comings and goings and looked at him with spurning eyes. It seems as if the relationship between Kyosuke and his sister, now 14, will continue this way forever. One day, however, Kyosuke finds a DVD case of a magical girl anime which had fallen in his house's entranceway. To Kyosuke's surprise, he finds a hidden eroge inside the case and he soon learns that both the DVD and the game belong to Kirino. That night, Kirino brings Kyosuke to her room and reveals herself to be an otaku with an extensive collection of moe anime and younger-sister-themed eroge she has been collecting in secret. Kyosuke quickly becomes Kirino's confidant for her secret hobby. The series then follows Kyosuke's efforts to help his sister to reconcile her personal life with her secret hobbies, while restoring their broken relationship and coming to terms with their true feelings for each other.
Characters
Main
Kyosuke is the 17-year-old protagonist of Oreimo. He has a distant relationship with his sister, and feels that this will never change. However, this suddenly changes when he finds one of her eroge and, after confronting her with it, learns that she is an otaku. Through this experience he realizes that he knows very little about his sister, including her being a model as well as an exemplary student. He decides to become more of an older brother to her. Despite Kyosuke being older, his sister is generally the dominant person in their relationship, with Kyosuke only standing up to her in truly serious situations. Kyosuke initially claims to prefer a relatively peaceful and simple life, but grows to enjoy spending time with his sister as well as the drama she causes to the point where he becomes lonely when she is not around. Kyosuke helped Ruri make friends and joins the Game Research Club with her during his third year when Ruri becomes his junior. Kyosuke dates Ruri during summer vacation but she breaks up with him. In the Oreimo: Kuroneko spin-off manga, the two wind up back together ten years later as an alternate ending to the canonical story written in the original light novels. In the past, Kyosuke had good grades and was the fastest runner in his elementary school. He also had the tendency to shoulder everything himself, thinking that there was nothing that he could not achieve, and often said "Leave it to me". However, after a hiking accident, Kyosuke was convinced by Manami that he should not try so hard at everything, which drastically changed his personality. He turned into someone who only desired to live a normal lifestyle, and his studies and athleticism worsened over time.
Kirino is Kyosuke's 14-year-old younger sister. She is normally mature and independent for her age. However, this is a facade and she only reveals her true personality—immature, abusive, and ungrateful with an aggressive, tsundere-like character—to Kyosuke, whom she orders to play her games and care for the characters, only to accuse him of being a pervert and a lolicon. She is secretly an otaku with an obsession for "little sister"-themed eroge, as well as the children's anime series Stardust Witch Meruru. Despite her interests, she states she does not know why she started liking eroge and denies having a brother complex. Nevertheless, she frequently forces Kyosuke to spend time with her, whether it is playing games or taking her out, but denies that she actually enjoys the time they spend together.
Ruri is a 15-year-old otaku girl who lives near Kirino and later enrolls in Kyosuke's school. She often wears Gothic Lolita clothing based on a character from her favorite anime, even during hot weather, and will sometimes add cat ears and a tail. She calls herself and wears contact lenses to make her blue eyes appear red. Due to both of their tsundere-type personalities, she constantly clashes with Kirino. However, both girls genuinely care for each other and value the time they spend together. Like Kirino, Kuroneko is very prideful but is willing to swallow her pride to achieve a goal. Unlike Kirino, who likes little sister–themed games and magical girl anime, Kuroneko enjoys teen-centered fantasy anime. She often mentions "dark magic", claiming that she has it. She is noted to have a very large vocabulary - Kirino once comments that she needed to use a dictionary to translate her novel. Kuroneko has two younger sisters, Hinata and Tamaki, whom she cares for dearly, although they and her mother worry about Ruri when she is in otaku mode. At school, Kuroneko wears normal clothes and at home takes care of her younger sisters. She later joins the video game club after she enrolls into Kyosuke's school; she is very good at playing video games. She dates Kyosuke for over summer vacation before breaking up with him. The Oreimo: Kuroneko spin-off manga, written by author Tsukasa Fushimi, sets an alternate ending to the original canonical story. Ruri still breaks up with him as to not upset Kirino, but he tells her to wait for him. In the manga's epilogue set ten years later, the couple are married, and have at least three children together.
Saori, under the alias , is the leader of the "Anime Girls Unite!" group on the Internet, whom Kirino encounters in a meet-up. She wears very thick glasses (shown as swirls) and speaks with an exaggerated tone. She is a fan of Gundam (her alias is named after the character, Quattro Bajeena) and is also a collector of their model kits. Despite her general appearance in public, Saori is actually from a wealthy family and speaks formally when not with her friends. As Kyosuke notes, Saori is drastically different in person as compared to how she communicates over the Internet or the phone. According to Kyosuke, she dresses as a stereotypical otaku, but has the body of a supermodel. She is tall and usually has to have cosplay costumes tailor-made for her. Despite being a middle school girl around Kirino and Kuroneko's ages, she is around the same height as Kyosuke, which surprises him when he first meets her. Despite her cheery attitude, Saori is quite lonely, living by herself, and has always feared that one day her true friends (Kirino, Kyosuke, and Ruri) will leave her in a similar way that her older sister (who married and moved away) left her. The reason she set up a hobby group of her own is that she was "just the sister of a member" of her sister's hobby group "Pretty Garden," and was severely disappointed and angry when the group eventually dissolved after her sister moved away.
Ayase is Kirino's classmate who is her best friend and also works as a model. She admired Kirino for being seemingly perfect in every way and she used to have a crush on Kyosuke, thinking of him as Kirino's caring brother. She was greatly disappointed when she found out about Kirino's otaku hobby and how Kyosuke was aware of it and helped support it. Ayase later reconciled with Kirino, but not as much with Kyosuke. Ayase is normally a friendly, nice, and refined girl, but becomes agitated and somewhat violent at the thought that she is being lied to, which she hates above all else. She also believes what she hears on the news, thus explaining her disapproval of anime and manga, calling it a disgusting hobby, especially eroge, due to the media's portrayal that otaku will eventually become criminals (a clear reference of the Tsutomu Miyazaki case). Once she develops a dislike and contempt for someone, she shows a much ruder and even hostile side of herself. She stubbornly maintains a strong dislike and disrespect for Kyosuke, convincing herself that he is really the pervert she persistently calls him. She becomes good friends with Manami and often confides private matters to her. She eventually overcomes her prejudice and harbors romantic feelings for Kyosuke.
Manami is Kyosuke's childhood friend. She wears glasses and is described as "plain", something she views as a compliment from Kyosuke. She has a crush on Kyosuke and blushes whenever he compliments her. Due to the amount time they spend together, people around them assume that they are dating. Kyosuke explains that although he does not have feelings for her beyond being close friends, for some reason he does not like the idea of Manami having a boyfriend. Kyosuke is unaware of the many times that Manami has attempted to become closer to him by trying to do things that couples do and how she is willingly doing things to please him in any way, such as cooking and cleaning. According to Kyosuke, her speech patterns resemble those of a grandmother or an old lady. After Kyosuke's accident it was Manami who convinced him to stop trying his best in everything, and made him into the average person today, which severely disappointed Kirino and caused the rift between her and Kirino. She manages to make up with Kirino after Kyosuke gets them to talk. Manami later confesses to Kyosuke but he rejects her.
Kanako is Kirino and Ayase's fellow friend, classmate and model, who sometimes swaps between a cute and a bratty personality. She is a talented singer who dreams of becoming an idol and attends many auditions. She frequently goes to karaoke and is capable of perfectly remembering any song that she has heard once. She is unaware of Kirino's hobby and generally finds anime childish and otaku disgusting, though on one occasion she was tricked into cosplaying as Kirino's favorite anime character, Meruru, for a contest and won. Despite winning the contest, she was disgusted by what she had gone through, but liked the idea of being praised and the event even helped her career. She later realized that Kyosuke, who acted as her manager, was Kirino's brother. She also asked Manami to teach her to cook in order to be able to cook for her parents.
Kōhei's little sister and a member of the Games Research club, as well as Ruri's classmate. Similar to Kirino, she has an obsession with eroge, albeit she prefers hardcore yaoi. She even fantasies about her other clubmates, imagining her brother and Kyosuke as a couple and becoming visibly disappointed when Kyosuke assures her that he is straight. The relationship she has with her brother is quite strong yet it is unclear how they feel about each other. She joined the Games Research club in order to learn how to become a games designer. She is also very good at games, and skilled in programming. In volume 12, she ends up dating Makabe.
Supporting