14-year-old (later 15) Kirino, the titular imouto (little sister), is a model student with excellent grades, competent athletic skill and great popularity. On the other hand, she's also an otaku with a fetish for Little Sister Heroineeroge. Kyousuke discovering her double life is what starts their first serious interaction in years. Eventually, Kirino opens up her otaku personality more thanks to her brother and gains friends in that world.Kirino claims she keeps the 2D and 3D worlds separate, but gets irritated when she sees Kyousuke interacting with other girls. It gets to the point where she claims she has a boyfriend just to make Kyousuke (who has Kuroneko) jealous. In the eighth volume of the Light Novel, after Kuroneko dumps Kyousuke, Kirino pulls a role reversal, comforting him and confronting Kuroneko about breaking his heart. After a heated argument, she admits that she was about to ask Kyousuke not to date anyone, but decided to let Kuroneko have him because she recognized how hard it must have been for the shy Kuroneko to get the courage to ask him out. She admits to being a brocon at the end. This is reflected throughout volume nine. She's still a tsundere, but much more open about the brocon/siscon relationship she and Kyousuke have.
In Volume 9 of the Light Novel, she's openly comparing how much of a siscon her brother is with Sena, and even gives Kyousuke a False Start confession at the end.
By Volume 10, Kirino and Kyousuke are often seen holding hands, and are the subject of some rumors around the neighborhood. Yoshino forces Kyousuke to move out, ostensibly to study for exams, but also to separate the two from getting too close as she sees it.
Kirino always wanted to marry her brother since she was a little girl. They eventually start dating and hold a fake wedding. They do break up and say they will be normal siblings though it is implied that they are still secretly together at the end of the novel.
On the other hand, the manga does the same, but with her deredere side.
Clingy Jealous Girl - Kirino tends to get a bit snippy if Kyousuke's been spending a lot of time without her, especially if she knows it's with another girl.
She suppresses this impulse in Volume 8 and episode 8 of season 2 to allow Kuroneko and Kyousuke to date unmolested, even though it eats her up inside. He's rather surprised by her lack of reaction when he tells her he's dating Kuroneko.
Her jealousy also shows up a lot in the Visual Novel, where she will likely confront Kyousuke at some point in anyone's route asking where he has been.
She goes as far as to move away again in one of Manami's endings.
She also has a rather heartbreaking exchange when she finds out Kyousuke and Ayase are dating in Ayase's route. Interestingly, Kirino will accept their relationship only if Kyousuke confesses to her that he loves her as much as he loves Ayase, which leads to the famous "Ayase baby" ending where she happily supports their relationship in the present and the future.
In episode 6 of the first season, she kicks his door and his chair at the table. Despite having a new hugging pillow, she can't fall asleep because she knows he's sleeping at Manami's house.
Later in episode 11, she gets incredibly annoyed at Manami being at their house, and sets ridiculous demands such as cleaning their living room, which Manami more than happily agrees to. Later she tries to sabotage Kyousuke by placing her laptop in his room with an eroge playing, as well as laying a bunch of his porn mags on his bed. It hilariously backfires as Manami isn't offended at all, but rather is intrigued that all of those mags and the eroge have Mega Nekko girls...
After seeing Kuroneko and Kyousuke getting along a bit too well in episode 6 of season 2 and volume 7 of the light novels, Kirino initiates Operation Jealousy on him, by claiming to be dating Mikagami, the boy they met at comiket earlier who's an Otaku and works at the same agency as her.
Closet Otaku - Finding people to talk to about her hobby is what kicks off and drives the plot for the first few volumes.
Already broke down crying in frustration◊ in the first light novel alone (Episode 3 of the anime, Chapter 10 of the manga) while confessing to Kyousuke that their father had discovered her eroge and scolded her badly.
Again in Episode 15 (True End), when she confesses to Kyousuke how much she missed playing them throughout her stay in America.
Once more at the latter half of Volume 7◊ (Season 2 Episode 6), as she's venting out her frustrations at Kyousuke over spending more time with Kuroneko and Manami than her.
Cute and Psycho - In a hidden route of the PSP Visual Novel, Kyousuke and Kouhei discover an 8-bit shrine under their hotel in Kyoto. Akagi wishes on the shrine that they're never separated from their little sisters for the rest of their lives, and as a result Kirino turns scarily overprotective, getting the Ayase-style murder eyes, forbidding Kyousuke from meeting or mentioning anyone besides her and then gripping him so hard she breaks his arm right at the end.
False Start - Kirino says something that's drowned out by the crowd noise at the end of volume 9. Whether it's just a thank you or a confession is left unresolved, but Kyousuke seems to have gotten the message.
First Name Basis: The fact that she's on one with Kyousuke is a given reason why their parents send him off to live by himself for a bit. They saw it as them getting a little too close (and considering they think the siscon eroge are his).
Hair Colors - Her hair is explicitly stated to have been dyed that color right at the start of the light novels.
Happily Married: She marries Kyousuke in a fake wedding in the final episode of season 2, then they immediately break up to just be normal siblings.
Hard Work Hardly Works - Completely averted. Kyousuke notes that Kirino is not really talented at running, but she makes up for that by training really, really hard. Unfortunately, this falls apart when she is pitted against people who both trains equally hard and are really talented.
It's All About Me - Kirino starts out like this, but improves greatly over the course of the story. It's implied later on that she acted like this earlier to hide her embarrassment in typical Tsundere fashion.
I Want My Beloved to Be Happy - After the incident with Kyousuke telling her he doesn't want her dating other guys, she was about to tell him the same when she found out Kuroneko was about to confess to him. She decides that being jealous is better than Kyousuke being sad and denying her best friend a shot at happiness, especially knowing how shy Kuroneko really is.
Lack of Empathy - Although even anime Kirino seems to get some eventually, as shown in Episode 9 when she plays an eroge and finds herself in Kyousuke's shoes. This is explicitly pointed out in the DVD Commentary and expanded on in the PSP Visual Novel.
Laser-Guided Amnesia - In the PSP Visual Novel, Kirino catches this through a combination of her jealousy towards Manami going with Kyousuke on the class trip and Kuroneko pointing out how similar Kirino's situation is to an eroge and telling her that she would lose sense of reality. It only affects her memory of anything related to her otaku hobby, including all development of her relationship with Kyousuke. The "convenience" of how exact this is is lampshaded immediately and repeatedly.
Manic Pixie Dream Girl - Kirino is manic to an extent, and looks the part, but it's actually Kyousuke who brings Kirino out of the solitude caused by her hobby. On the other hand, Kyousuke also starts to have a much more interesting life as a result of his actions, so it works both ways.
Ms. Fanservice - This isn't really a fanservice series (one can even count the total amount of Panty Shots on the hands), but almost all fanservicey shots come from Kirino.
Not Blood Related - In an If route (which is even less canon than the other routes of the PSP game), Kyousuke discovers that he's not actually Kirino's brother. As soon as both siblings are aware of this, they almost immediately start a relationship. The night Kirino finds out, she tells Kyousuke to sleepnote what definition of sleep is ambiguous, but she's putting on her kissy face while she says it with her so she can be sure he won't move away now that he knows he's not related to the family.
Obfuscating Stupidity: She comes off as bubbly and obsessed with her hobbies, but the anime and manga make it clear that she is very crafty and manipulative. On a good day, she's also an excellent liar and skilled at otherwise hiding the truth.
Parody Sue - Other characters (such as Kuroneko) are annoyed at how perfect she is at (almost) everything — academics, athletics and even modeling. Except she actually worked hard to earn her skills, and has to rely on Kyousuke or Kirino to help her in matters relating to anime, manga, games or light novels. Come Volume 11, it is revealed that the reason Kyousuke is also annoyed at her present self is because she reminded him of his former self, and subsequent developments reveal that Kirino's talents sprang from her attempts to "surpass" her brother.
Pet the Dog: Kirino gets some rare moments where she's genuinely or at least somewhat nice to Kyousuke.
The first is in the second half of season 1, when she throws the maid party with Saori and Kuroneko to thank him for all his help and advice.
The second big one is in episode 9 of season 2, after Kuroneko breaks up with him. While she does put him in a chokehold move briefly, she does seem to go out of her way to help him find where Kuroneko went and why she suddenly dumped him.
Put on a Bus - She is away in America for most of Volume 5 of the light novel and the ONA episodes.
Panty Shot - The camera does not want to cooperate with those short skirts she likes to wear.
Tears of Joy - At the end of episode 14 of season 2, after nearly two year of self-denial and inner struggling, she finally accepted the fact that she loves Kyousuke more than as an older brother, and shed tear of joy when he confessed to her.
Tsundere - Kirino in the anime is a Type B towards Kyousuke and Kuroneko and very heavy on the tsuntsun; other versions are much more evenly balanced. All, eventually, defrost to at least some extent. The PSP If route where she and Kyousuke are Not Blood Siblings heavily implies that the heavy tsuntsun is entirely because of her anxiety about her Big Brother Attraction. When that obstacle is removed she immediately goes 90% deredere, and tells Kyousuke that she actually always liked him, even before the events of the story.
Used to Be a Sweet Kid - There was a time when Kirino was a cute, loving little sister. Then Kyousuke just had to give up the cool figure he always presented to Kirino, breaking her heart. No wonder she Took a Level in Jerkass.
All 17-year-old [later 18] Kyousuke wanted was a normal life — a boring job, a boring wife, etc. — save for his lack of communication with Kirino for years. All that changes when he finds a Magical Girl DVD case with an eroge inside after bumping into Kirino. He's then brought into Kirino's world as her confidant and helps her along the way. Along the way Kyousuke begins to see things more and more in an otaku life, eventually using Visual Novel terms in his decisions and choices.Kyousuke is easily intimidated by Kirino, but stands up for her when needed and takes a lot of the abuse that should be directed at her. Although he claims to hate her, the main driver of the plot is his gradually thawing relationship with Kirino.
Abhorrent Admirer: Invoked by him for fun. Flirting with Ayase until she attacks him seems to literally be how he gets his kicks. He tries to tone it down later in the series, because he can see where it can be misleading and dishonest when its just for fun.
The Ace: Resembled one of these three years ago with good grades, a good athletic people and an overzealous enthusiasm for helping people.
Broken Ace: Essentially gave up trying to be special due to events revealed in volume 11.
Adorkable: In-universe, most of his friends consider him awkward and a little pathetic at times, but endearing. Interestingly, very rarely does anyone actually see his competent and determined side, which the audience knows is what usually saves the day.
Big Brother Instinct - A major plot point is that he was so jealous of Kirino's success that he turned this instinct off until the beginning of the series.
Bishōnen - A borderline example. He's arguably full blown in the manga, though.
Broken Pedestal: Kirino used to idolize him when she was younger because he excelled at everything. But then he started becoming lazier, which shattered his image in Kirino's eyes.
Brother-Sister Incest - People like to joke about how close Kirino and Kyousuke are. The novels started out pretty vague, but in Volume 9 he and Kouhei actually have a contest about whose little sister was cuter. Kyousuke actually wins the later contest their little sisters have over whose brother is the biggest siscon.
The Casanova - DVD Commentary Kyousuke is quite good at chatting up any female co-hosts, even if the lines shouldn't really be working so well...
Kanako: You say those heart-melting lines to all the girls, don't you?
Kyousuke (sparkling) : Don't misunderstand. You're the only one I've asked about the color of her panties.
Kanako (blushing): Oh...in that case, I'll let it slide...
Chick Magnet: Canonically, he at least has Manami, Kuroneko, and (as of season 2) Ria, Kanako and Ayase crushing on him (with Kuroneko becoming his girlfriend temporarily). In the PSP game, he can romance Saori, Ayase, and, with the right ending, even Kirino herself.
Crazy Jealous Guy: Acts rather hostile towards Mikagami, Kirino's boyfriend at first, to the point where Kirino slaps him and forces him to leave the room when she invites him over to her house to meet their parents.
Cry Cute - A rare male example, courtesy of Kirino actually apologizing to him. In the anime, it's after she throws him a Meido party as restitution for disgusting him with her appalling treatment of Manami. In the novel, it's after said party ended up a failure, with Kyousuke being pushed too far by Kuroneko's manga and Kirino and Kuroneko beaning him over the head with a chair for seeing their 3D analogues get stripped naked in a custom Siscalypse game Saori brought.
Guile Hero: Often, he's left with no recourse but quick thinking, fast talking, and the occasional Zany Scheme to get himself or his friends out of hot water.
The Heart: He's the one who keeps Kirino and their friends together, whether through mediating between them or just listening to their problems and trying to help them. Saori even threw him a maid-party to show her appreciation of this.
Hidden Depths: In-universe, to some extent. Judging by the not-really-canon-but-generally-reflective-of-it in-character DVD commentaries, most of the other characters in the show aren't really aware of how self-sacrificing or determined Kyosuke can be. Saori and Manami are astounded (speechless, even) when seeing for the first time the scene where Kyosuke convinces his father to let Kirino continue her anime and gaming hobbies, throwing his own reputation out the window and risking a beating. Even though Saori already had a thing for Kyosuke, she still considered him vaguely pathetic up until that point.
I Just Want to Be Normal - Kyousuke's outlook on life before he reconnects with Kirino. He starts going through withdrawal symptoms when she's not around.
In-Series Nickname - He's called "Sexual Harassment Sempai" by Sena, Kuroneko repeatedly calls back to this whenever she perceives him acting a bit perverse.
Not to mention "Sexual Harassment Manager" after Ayase lies her ass off to Kanako and says Kyosuke was fired from being Kanako's manager due to hitting on Ayase too much.
Large Ham: He tends to do this from time to time, such as telling his dad the eroge games were his, and that he was forcing them on Kirino.
Master of the Mixed Message: He tells Kouhei that he's not dating Manami, has no intentions of doing it, but also won't be okay if she dates another guy. Later on, Ayase claims he's a pervert who likes to sexually harass girls. He doesn't deny it, but claims he only does it to her, to the point where she gets mad at him because he jokingly promised to marry her.
Nice Guy - One of his defining qualities. Although he hates to do it, he will often go to great lengths to help out Kirino, even if its largely unappreciated, and this is one of the main reasons why so many of the girls in the series falls in love with him.
It's not at all limited to Kirino—he'll do the same for just about anyone who asks him for help with anything.
Not so Above It All: In episode 2 of season 2, Ayase complains to Kyousuke that Kirino is way too obsessed with one of her newest gal game. He promises to help her snap out of it, and when he talks to Kirino later, she makes him play the game as well. He starts getting into the game just as much as Kirino did, to the point where he makes the same goofy faces Kirino did, and brushes off Manami in a very rude manner.
Oblivious to Love - Manami's anyway. He gets a bit better with Kuroneko. He goes to a rather frustrating extreme in Manami's route of the PSP game, where he continues to be kind of blase about the whole thing even after they start going out, while Manami is practically exploding with adoration for him.
Unreliable Narrator - Part of the reason Kirino is generally more lovable in the novels is because Kyousuke is giving a biased account of her, edited through the filter of his initial dislike and denial of her and her feelings. On the other hand, the manga also shows Kirino to be very vulnerable and awkward at times, which Kyosuke also can't perceive.
What You Are in the Dark: A consistent element in his characterization is that the majority of his friends never see him at his best moments and are generally oblivious as to just what he's capable of.
A member of the same online community as Kirino and Saori, as well as a foil figure for Kirino. A fan of Maschera (which looks like a lovechild of Code Geass, Death Note and Darker than Black), her arguments with Kirino about the direction anime is going can sometimes be construed as arguments on the genre as a whole. Despite their arguing they are quite close to each other.Kuroneko's relationship with Kyousuke also developed quite a lot. First seeing him as an older brother who does just about anything for his bratty younger sister, she tells Kirino that's she's jealous and calls Kyousuke "nii-san". In the 5th novel she starts attending Kyousuke's school and at that point calls him sempai. And at the end of volume 7, they enter a relationship.
A-Cup Angst: In episode 8 of season 2, she puts on an entirely new outfit which Kyousuke says makes her sexier. When she asks him what makes it sexier to him, he mentions that it makes her boobs look a little bigger. She then dejectedly walks away, forcing him to carry her bags and chase after her.
A Day in the Limelight - Two of the four net episodes focus on her, as is the case with volume five of the light novel, and episodes 7 & 8 of season 2.
Aroused By Their Voice - Kyousuke is a bit stimulated when he hears Kuroneko's voice in the vocal foley for a game they were making.
Loners Are Freaks - She doesn't get along well with her class, although Kyousuke keeps meddling to get her to socialize a bit more. It works.
Love Triangle - Kuroneko, Kyousuke and Kirino are the main love triangle. She ends up going out with Kyousuke in Volume 8 of the Light Novel, only to break up with him at the end of summer. This is partly because she realizes that she likely can't win against Kirino in the end, as well as not wanting to hurt her friend (see this disturbing drawing in her journal lamenting that feeling◊). The end of the volume implies that she'd quite like to be together with both of them.
Panty Shot - Saori bluntly points out that Kyousuke might be getting quite a view from Kuroneko in the first scene of the Visual Novel, which serves as an introduction to the real time conversation system as he desperately tries to calm Kirino down. There's also a blink-and-you'll-miss-it one in Episode 13.
Polyamory - The end of Volume 8 implies she's in favor of this answer to the Love Triangle problem. She blurts out that she's okay with Kirino and Kyousuke <censored>ing in volume 10.
Relationship Upgrade - Becomes Kyousuke's girlfriend in the eighth Light Novel and episodes 7 & 8 of season 2...then breaks up with him at the end of their summer vacation.
Romantic Runner-Up: And probably because of that, ended up bringing Kyousuke and Kirino even closer together than before. He ends up rejecting her in the OVA's for season 2, and while she ultimately accepts it, she screams out in anguish and curses him too.
Debatable, since she actively trying to force Kirino to admit her feeling and making both siblings to be closer.
Spin-Off - Kuroneko has her own manga, Ore No Kouhai Ga Konna Ni Kawaii Wake Ga Nai (My Underclassman Can't Be This Cute).
Sugar and Ice Personality - She is mostly cold to everyone, but can be very sweet towards Kyousuke, the object of her affection. This contrasts with Kirino's Tsundereism
Vitriolic Best Buds - With Kirino — no matter how much either denies it — and to a lesser extent, Sena.
What the Hell, Hero?: Gets called on this in episode 9 of season 2, after suddenly breaking up with Kyousuke, then refusing to answer his calls or texts, moves away, and transfers to another school without telling him.
Yamato Nadeshiko - When Kyousuke first meets her, he thinks that she has the appearance of a traditional Japanese beauty. Her personality, however, couldn't be further from this type.
Older than They Look - Because of her fashion style and body type, Ruri looks younger than her peers and even characters younger than her, like Kirino and Ayase.
Moderator of Kirino and Kuroneko's home online community, Saori looks like a stereotypical otaku who uses weird speech mannerisms, uses really thick glasses (with swirls), and wears awkward clothing. But don't let first impressions fool — Saori is actually a wealthy socialite who is quite traditionally beautiful. She even has an impeccable fashion sense and speaks in a traditional high-class style while not playing as "Saori Bajeena". Volume 9 reveals that she got both her otaku fashion sense and her speaking style from Kanako's older sister Kanata, who even gave her the swirly glasses.Saori is quite close to Kuroneko and Kirino, considering them both her closest friends, even having to stop them from tearing each other apart sometimes.
Arranged Marriage - In the PSP game, Saori is engaged by her parents to a 40(!) year old business heir who wants her to throw away her otaku hobby. The main plot driver of her route is Kyousuke getting her to stand up to her parents and fiance to defend her identity.
Beautiful All Along: In the anime, she can be seen very briefly without her glasses in the mirror in one episode. She is first seen fully without them in episode 3 of season 2, and is completely shocked by the fact that her friends caught her off-guard without them on when they attempted to visit her for a surprise birthday party. Kirino later mentions this trope to her.
Cat Smile - You'll see it in the manga and a few times during the anime.
Cosplay Otaku Girl - She comes up with the idea of the maid party for Kyousuke to apologize for Kirino and Kuroneko planning the Porn Stash trap for Manami to find. The anime implies this was partly to have an excuse to dress herself and her friends in custom made maid outfits she ordered. Also, in the PSP game, she shows Kyousuke a stack of cosplay photos she took to try and "get the otaku urges out" of her in preparation for her Arranged Marriage, including a Sarashi Bikini kind of outfit that makes Kyousuke do a Spit Take.
Foreshadowing: In the manga, when Kyosuke says he's having trouble with Kirino's video-games, she prescribes a regimen of taking a rifle, going everywhere with it, taking turns at right angles and swiveling like a turret to turn, FPS-style. We later learn that her older sister was an extreme gun-nut, introducing Saori to the world of obsessive fans that she would later embrace. Although her sister more or less dumped her for a husband later on, their bonding through gun-play was the turning point in Saori's life.
Huge Schoolgirl - Subverted. She's a cheerful leader type with excellent social skills, defying any height complex and the socially inept otaku stereotype. Double Subverted in that she actually is cripplingly shy; the otaku persona is a coping mechanism with which she practices the only real social skills she knows. The first meeting she has in the series with Kuroneko, Kirino, and Kyosuke? That was her first time trying to make new friends, too.
It Was a Gift - Saori's glasses, and really her whole otaku persona, were borrowed from Kanako's older sister Kanata, who Saori admired and introduced her to anime and manga.
Otaku Surrogate - Even plays up the part by wearing stereotypical Otaku clothes.
Out of Focus: She is a supporting character at best in the first season of the anime, whereas in the light novel she's given much more emphasis. Episode 3 of season 2 averts this trope by devoting it entirely to her back story, giving much needed characterization and how she became an Otaku Surrogate in the first place.
Platonic Life Partners: She's the only one of the main girls that doesn't fall in love with Kyousuke. Averted in the visual novel if you play her route though.
Playing Against Type - After a decade of playing emotionally-reserved and dead-serious warriors like Kanu Unchou of Ikki Tousen, Hitomi Nabatame finally sinks her teeth into a bright and upbeat role like Saori.
Screw the Rules, I Have Money!: While it doesn't really seem like she does anything too different, in episode 11 of season 2, while all of the girls are fighting over Kyousuke, he mentions that ever since they found out about her other life, she seems to flaunt her money quite a bit more openly, after she says she's the best person due to her wealth.
Shrinking Violet: She used to be one. In her first meeting of her sister Kaori's friends, as seen in episode 3 of season 2, she hides her face behind her hands when she first introduces herself to them. She gradually grows out of this trope over time.
Team Mom - Again to Kirino and Kuroneko, both in the forums and in the outside world.
They Do - In the best ending of her Visual Novel route, she marries Kyousuke while they're still in high school due to her parent's prodding. This is pretty abrupt since, unlike the other routes ending in marriage, before the last scene their relationship isn't treated as definitively romantic at all.
Kyousuke's childhood friend and probably the simplest member of the cast. Plain and wearing glasses, she has a crush on Kyousuke and spends lots of time with him. Kyousuke knows nothing about it; nevertheless, he finds Manami comfortable and considers her part of the family.Kirino dislikes Manami, most likely due to the fact Kyousuke spent more time and is in a better relationship with her than his own younger sister. As such Kirino insults/ignores her whenever she sees her. Kuroneko acts this way too when she starts seeing Kyousuke as more than just a friend. It's revealed that she's the cause of the Kousaka siblings' cold war. She is thus, by default, the main antagonist of the series.
Babies Ever After - Manami's best ending in the PSP game has her giving Kyousuke some nice tea after they're married, and nonchalantly telling him that she's pregnant. Kyousuke's reaction is excited happiness, to say the least.
Beware the Nice Ones - It's hard to tick her off, but she's apparently very scary when she is angry. So scary even Kyousuke cringed at the possibility of angering her in the eight light novel. She's also the main reason Kirino and Kyousuke have such a bad relationship
In episode 16 of season 2, after having been Demoted to Extra for a very long time, she finally snaps when she has a "final fight" with Kirino. Kyousuke thought they were just going to talk, but Manami literally delivers a gut punch to Kirino to let her know how she feels regarding their relationship. Perhaps not too surprisingly, she's the only one they've told who isn't pleased at all about it.
Big Bad: The main problem for a while was Kirino and Kyousuke's strained relationship, Manami started that strained relationship, do the math.
Derailing Love Interests: Near the end, it is revealed that she destroyed Kirino and Kyosuke relationship years ago out of jealousy. On top of that, she dragged Kyosuke down to become lazy and apathetic, so he wouldn't be out of her league, by manipulating his self esteem and guilt over some accident during mountain trip. There was little to none indication that she was anything that cute and plain childhood friend before this reveal.
The novel made it unclear in this matter. She didn't destroy Kirino and Kyousuke's relationship, but when Kyousuke was very vulnerable due to his failure with Sakurai, she gave him some advices (unclear if she did it intentionally or not). And while those advices seemed good in her POV, Kyousuke interpreted them in a way that caused him to turn lazy, which in turn destroyed his relationship with Kirino.
Foil - Manami is what Kirino is not: nice to Kyousuke, plain, and almost pathologically normal in every way. Kyousuke makes this comparison himself when she's first introduced. No wonder Kirino (and eventually even Kuroneko) dislikes her.
Generic Cuteness - She's not considered that good-looking In-Universe, but through this trope she looks about as cute as the other girls, odd haircut notwithstanding.
In-Series Nickname - Kuroneko calls her "Belphegor" even before actually meeting her, based on Kirino's stories that she's a seductress underneath that sweet exterior.
Jerkass Has a Point: Her criticism of Kyousuke's relationship with Kirino was brutal and her fight with Kirino may have gone too far, but she had a valid point when she told them of how difficult it'd be to have an incestuous relationship. Kyousuke even acknowledges that she's right, but goes for it anyway.
Persuading Kirino that her feelings of admiration towards Kyousuke were unnatural, and convincing Kyousuke that the reason for his troubles was his exuberance, and that he'd be happy living a life of Dismotivation, basically creating the Kousaka Cold War; Jesus, Manami!
Odd Friendship - She became friends with Ayase at some point. In the anime, she claims that she ran into Ayase a few times in various places after he introduced them in an earlier episode.
Out of Focus - She becomes less and less prominent in the later novels and most of season 2.
She Cleans Up Nicely - An If route shows her becoming an idol with a different hairstyle and no glasses, and she arguably looks as cute as the girls who are professional models. Of course, Generic Cuteness may be in effect here.
Shipper on Deck - She tells Kyousuke to go after Ayase in the eighth volume of the light novel.
Tranquil Fury: Surprisingly even when she's mad, she doesn't lose her composure too much. The exception is in episode 16 of season 2, when she snaps and attacks Kirino after the latter taunts her about having "stolen" Kyousuke away, but even then, shortly after Kyousuke breaks up the fight, she seems eerily calm when she's asking him a couple of ArmorPiercingQuestions, and later slaps him while smiling and telling him his reply of choosing Kirino over her was the worst possible one.
Turn the Other Cheek - She takes the jealousy-motivated rudeness from Kirino and Kuroneko in stride and doesn't even seem cross with them. However, unlike everyone else whom they've told about their relationship, in episode 16 of season 2, she does avert this trope and attacks Kirino when the latter taunts her repeatedly about having "stolen" away Kyousuke.
Walking Spoiler: She became one in season 2, when it was revealed that she is the closest the series has to a Big Bad.
Yamato Nadeshiko - As far as her personality goes, she's probably the closest girl in the show to the ideal Japanese wife.
Kirino's classmate, coworker, and best friend. Ayase can be very protective of Kirino and cares for her quite a bit. However, accidentally learning of Kirino's hobby causes a rift that Kyousuke has to fix (by sacrificing his dignity and claiming he is "corrupting" Kirino with his eroge collection). After that she tolerates Kirino's hobby and tries to support her.Ayase initially thought Kyousuke was a cool older brother and maybe even had a little crush on him (which, she kinda did), only for that to change to contempt after being fooled by Kyousuke into thinking he is "corrupting" Kirino. However she'll still go to him for help with making up with Kirino along with getting her items related to her hobby.
Babies Ever After - Only a possible ending with Kyousuke in the PSP game, so it's not even remotely canon. Nevertheless, it caused quite a stir when it was leaked before the game's release.
Bitch in Sheep's Clothing - How she seems to act towards Kyousuke most of the time, partly because of him "corrupting" Kirino, and partly because he often teases her, such as jokingly asking her to marry him, which she uses against him a couple of times in the later novels. She does eventually utilize this trope less and less however.
She seems to act this way towards Kanako a lot, such as smacking her in the face in episode 1 of season 2. In episode 10 of the same season, Ayase wonders if Kyousuke is making Bridget nervous, but the latter denies it. Bridget is actually afraid of Ayase due to the mean look she makes when talking to Kanako.
Bi the Way: In episode 2 of season 2, after Kyousuke plays a new game that Kirino was getting too obsessed with, he tries to explain to Ayase what the game was like, and how the girl in the game looks and sounds almost exactly like her. As he explains it, she misunderstands him and with an excited expression, asks if Kirino wants to be lovers with her. He immediately rejects that notion.
Broken Pedestal - How she saw Kyousuke after he sacrificed his dignity and claimed he is "corrupting" Kirino. Still that does not stop her from approaching him whenever she needs help concerning Kirino.
Clingy Jealous Girl - In volume 10/episode 11 of season 2, she visits Kyousuke in his apartment early in the morning. Kuroneko arrives shortly afterwards, and both girls butt heads a bit as to why the other girl is visiting him so early, and at all for that matter. Ayase claims that since they broke up, Kuroneko shouldn't even be visiting "onii-san". But Kuroneko wonders what kind of relationship Ayase has with him, since she treats him like dirt.
A few chapters later, she also gets jealous that even Kanako is making food for Kyousuke while he's living alone. In episode 11 of season 2, when seeing Saori for the first time, Ayase eyes widen quite a bit at seeing yet another rival. Moments later, both Ayase and Kirino rush outside upon seeing Kanako handing Kyousuke some food, and both girls hilariously have the same exact movements and expression on their faces as they ask why he seems friendly with their friend.
Distant Finale - Her (in)famous Babies Ever After ending takes place an unspecified amount of time after the main story, but Kirino has been modelling professionally in Europe for at least a few years and freaks out over the prospect of being an aunt since that means she's getting older.
In episode 6 of season 2, when Kyousuke innocently asks her if Kirino has a boyfriend, she activates Yandere mode in her eyes, and begins questioning him on it. Her eyes scare him so much he crawls to the other side of the room, causing her to wonder why he did that.
Defrosting Ice Queen - Towards Kyousuke in the Visual Novel as well as the light novel and season 2 of the anime. She actually gets mad at him for "lying" about wanting to marry her in the Light Novel and season 2. This plot thread gets expanded to a full relationship in the Visual Novel.
Kyousuke loves calling Ayase "Lovely My Angel" as part of his flirting.note Incidentally, Kirino has what looks like a case/box with "Lovely Angel" on it in the box of her personal effects that she shows Kyousuke the night before she leaves, with a silhouette that looks very similar to Ayase. This may be the source of the nickname.
Her contact data appears under this nickname in Kyousuke's cellphone in season 2.
"Lovely My Angel Ayase-tan" is the name of a fanblog of Ayase in Volume 10.
Knife Nut: When she's taking care of Kyousuke during his prolonged study session, she gets him to study by non-lethally threatening him with a kitchen knife. She also flails it around when she finds some porno rags in his place.
Love Confession: Gives one to Kyousuke at the end of episode 12 in season 2. He rejects her, stating he already loves someone else, and she doesn't take it too well at first. But she eventually accepts his decision.
Moral Guardian - Ayase basically plays this role for the show over the subject of eroge. She does, however, start to loosen up and contacts Kyousuke to get Kirino the best gift she can (which would naturally be otaku-related).
Odd Friendship - She became good friends with Manami at some point during Kirino's stay in America.
Only Six Faces - She looks quite similar to Kirino doesn't she? Even her hairstyle is almost the same.
Fridge Brilliance - they're models, it would make sense that they would be chosen for that kind of appearance and hairstyle.
Unprovoked Pervert Payback - The epic kicks she gives Kyousuke sort of fits into this category. Unlike his relationship with any other girl, though, Kyousuke actively flirts with Ayase any chance he can get in the Light Novel and Visual Novel, so this may not be so unprovoked.
Vitriolic Best Buds - With Kyousuke after he fools her into thinking that he is "corrupting" Kirino. There are indications that the reason she still talks to him is because she doesn't really believe his story, but accepted it anyway to stay friends with Kirino. She confirms this in the PSP Visual Novel.
Played with in volume 10 of the Light Novel, where Ayase produces a kitchen knife out of nowhere as a housewarming gift for Kyousuke's new apartment. Kyousuke understandably panics, and Ayase wonders why he freaked out so easily just because he saw her with that knife.
In episode 2 of season 2, after playing the gal game Kirino and Kyousuke were playing earlier, Ayase develops that look in her eyes when she mentions wanting to team up with Kirino to kill onii-san (Kyousuke). Kirino is immediately put-off and declines it, while Kyousuke, who was watching from a short distance away, immediately realizes Ayase took the Yandere route in the game.
She has that look on her face again when Kyousuke asks her if Kirino has a boyfriend in episode 6 of season 2. It freaks him out so much that he crawls away to the opposite side of her room. She then wonders why he did that.
In a Flash Back during episode 10 of season 2, she gets a call from Manami regarding Kyousuke's girlfriend. The first thing Ayase mentions is killing her, but Manami calms her down to tell her that they broke up.
It's to the point where she uses this when Kyousuke rejects her love in episode 12 of season 2, claiming while teary-eyed she'll kill him if he doesn't go out with her.
In one of the anime ending themes, a chibi version of Ayase with a murderous, toothy grin on her face and a knife in her hand is running furiously towards what is supposedly an unknown soon-to-be stab victim. While little kitchen knives are flying in the background. And her episode titles are generally marked with drawings of knives.
Another of Kirino's classmates and model coworkers. Kanako has several layers, the first being a cute, short, musically talented girl. The second is a cold, heartless bitch. Beneath all that, however, she might just be a regular girl in the end after all.Kanako constantly goes to karaoke and tries out at idol competitions. She's even able to sing a song she's only heard once perfectly. All this comes in handy when Ayase tricks her into cosplaying as Meruru at an event to win an item for Kirino. Despite winning, Kanako feels disgusted, though the praise she received ultimately inspired her to go full-time.Come Volume 9 (Season 2 Episode 10), Kanako gets Ayase to bring back the manager (aka Kyousuke), because he was her first fan. It also implies that she would be okay with Kirino's hobby because her older sister Kanata is a mangaka.
A-Cup Angst - She's self-conscious about being flat-chested and undeveloped in the Visual Novel, to the point of teasing Kyousuke about being a lolicon when he shows some attraction to her. In both the Light Novel and the Visual Novel, she basically forces Kyousuke to fondle her chest.
Ascended Extra - She gets her own mini-route in the PSP game, as an offshoot of Ayase's route. In the sequel, her route is extended to be the same length as the other girls. The omake novel that came with the PSP game has Kyouhei married while living with his parents. Despite the fact that the wife is never named, it is implied by the exchange that the wife is Kanako.
Bitch in Sheep's Clothing - Acts cheerful when a job prospect comes up, but when not working or if the job turns out to be fake, she immediately loses interest. However, like Ayase, she starts to show her good side.
Blackmail Is Such an Ugly Word - In her mini-route, Kanako blackmails Kyousuke into paying for various activities in return for not telling Kirino that her "manager" was Kyousuke. Rather than blackmail, she calls it "courteous service for a lady," which Kyousuke can't help but laugh at.
Clingy Jealous Girl - In Volume 10/episode 11 of season 2, she wonders why Kyousuke is eating food made by other girls, when he should only be eating food she made for him. This while she herself is learning to cook (from Manami, who she got in touch with through Ayase). Like with Ayase, she butts heads with Kuroneko on this subject.
Genre Savvy: In Season 2 Episode 1, after Kirino returns from America, Ayase happily greets her. Kanako wonders if they're going lesbian, then immediately corrects herself and says it must be Yuri instead. It's because her sister Kanata likes those sorts of things too, hence why Kanako used that term despite not knowing about Kirino's hobbies at the time.
Hates The Job Loves The Lime Light - In Season 1 Episode 10, Ayase fooled her into wearing a Meruru costume due to her uncanny resemblance to said character. Although offstage she gripes about it, while she's performing on the stage, she seems to give herself entirely to the act as she sings and wows the audience.
Jerk with a Heart of Gold - Beneath that crass attitude she is surprisingly a decent person, going so far as to quickly accept Kirino for who she is upon learning of her secret hobby.
Lethal Chef: When she first tries to make some food for Kyousuke in Season 2 Episode 11, he states that it's not very good. She mentions that she's learning to cook in an attempt to mend her relationship with her parents.
Odd Friendship - She more or less befriends Bridget, the blonde girl she beat during the Meruru cosplay contest (who didn't have a very good impression of her offstage). At one point in the novel, Kanako protects her against an older man who seemed to be getting a little too frisky with her, only to find out that it was her father, but Bridget nevertheless appreciated the thoughts behind Kanako's attack.
Father of Kyousuke and Kirino. He has a no-nonsense home policy, which fits nicely with his career as a police officer. Despite his gruff exterior, he cares greatly for his family even if he doesn't show it. He even has clippings and articles all about Kirino's job.In the first novel he discovers Kirino's hobby and orders her to throw it all out. After Kyousuke convinces him to allow Kirino to keep it, he researches more into the otaku lifestyle to understand it better.
Overprotective Dad: When Kyousuke discovers him drinking himself out upon seeing Kirino with a boyfriend, he tells him that he refuses to give Kirino to anyone, and was even willing to risk his job as a police officer by knocking him out. Fortunately Kyousuke manages to talk him out of doing it, and says he'll go instead, since he feels the same way.
Pet the Dog - He has his moments, even if he isn't happy about issuing them (as seen at the end of Volume 1 and episode 3 when, with a frustrated expression on his face, he orders Kyousuke to do as he wishes with the eroge, even if he wants to keep it all, right after punching him in the face for being a siscon).
Reasonable Authority Figure - He had to be convinced about Kirino's hobby, but he also doesn't restrict his kids, such as not allowing Kirino to use her money how she wants, nor does he actively meddle in their affairs constantly like other parents. He also did some research about Kirino's hobby, and eventually became able to transcend common misconceptions about the otaku culture.
When Yoshino becomes gung-ho about Kyousuke and Kirino's supposed "relationship", it's actually he who decides to trust Kyousuke (though he segues that into kicking Kyousuke out of the house so he can prove worthy of that trust by passing his entrance exams).
Tsundere - Even pointed out in the DVD Commentary by juxtaposing footage of him and Siscalypse's tsundere character. The commentators are disturbed. Fumihiko Tachiki seemed to be having fun with this in Daisuke's second commentary appearance, putting on a vaguely effeminate tsundere voice during some of his "moments".
Daisuke: "...but don't get me wrong, I didn't do this for your sake."
Kyousuke and Kirino's mother and the force binding the family together. She happens to know about Kirino's hobby and Kyousuke's Porn Stash.
Reasonable Authority Figure - She doesn't seem shocked when Kyousuke tells her he knew about Kirino's secret hobby. She also doesn't make a big deal about him having porn either, but likes to poke fun at him for it.
Troll - Look at that face. Look at that smug face!
Kyousuke and Manami's classmate, and Sena's older brother. Kouhei keeps wondering why Kyousuke hasn't started dating Manami yet, even after he got Kyousuke to admit that he wouldn't let anyone date Manami.Like Kyousuke, his little sister is an otaku... except their relationship seems to be more risque than that between the Kousaka siblings.
Beta Couple - His relationship with Sena is quite similar to Kyousuke and Kirino's relationship, and often compared to theirs in the light novels. A major difference is that he has no problem with saying his sister is cute. At one point in the DVD commentary, when a possible Spin-Off is teased he says the name would have to be "My Little Sister is Cute!", causing much tsundere blushing on Sena's part.
Brother-Sister Incest - Implied, with Sena. It's to the point where he was looking to buy a sex doll that looked just like Sena... which he saw while he was buying her a gimp suit in a porn shop for her "research."
In volume 9, he has a contest with Kyousuke over whose sister is the cutest. Sena wins after kissing Kouhei on the cheek for a picture.
Handsome Lech - Kouhei is implied to be quite good looking and popular with the ladies. Of course, we only ever really hear about his relationship with his little sister and the perverse otaku baggage that brings...
A Class Representative, member of the Game Research Club, and Kouhei's younger sister. Sena seems to be a responsible, hard-working girl and acts more like a Student Council member than a Game Research Club member. But all that's a facade — Sena is quite the hardcore fujoshi.She and Kuroneko don't get along very well, which makes the fact that they share both the same class and club all the more frustrating for each other. Eventually, however, their relationship begins to mirror that between Kuroneko and Kirino when the former has to ask her help on her game.She and Kirino meet at the summer Comic Market during the summer break and become fast friends. She introduces Kirino to Boys Love, while Kirino talks to her about eroge, and both compare notes about their relationships with their older brothers. They have a contest to determine whose brother is the most siscon. Sena admits defeat after hearing that Kyousuke flew to America to bring Kirino back as well as breaking up with his girlfriend for her.
Beta Couple - Her relationship with her brother is remarkably similar to that of Kirino and Kyousuke, except with no pretense of hating each other.
Nightmare Fetishist - At first, she just seemed like a yaoi fangirl. And then her game came along and had anal fisting up to the entire arm; necromancer yaoi, and anal using the hilt of the Masamune. All in a single scene. She's actually surprised this proposal is rejected.
Shipper on Deck - For Kirino and Kyousuke. Specifically, "Kirino-kun" and Kyousuke, which she draws in a doujinshi that she sends Kirino.
In episode 7 of season 2, she said that she (and the entire game dev club for that matter) thought he was going out with Kuroneko for a while.
Tsundere - She's a Type B in that she only acts deredere to her brother Kouhei. This is especially obvious in the DVD Commentary for Episode 13, but can be seen in her interaction with him on the phone during the actual episode as well.
Women Are Wiser: Subverted. She seems to be the most composed, serious member of the gaming club. But once her yaoi fetish is exposed, all that goes out the window.
Yaoi Fangirl - So much so she fantasizes about one of her clubmates getting gangraped by the other members. Cue looks of horror and disbelief from her fellow club members when she blurts this out.
First encountered by Kyousuke while picking up Kirino’s eroge in Volume 4, Chapter 4/Episode 12 - True Route, Gennosuke is the president of the Video Game Research Club within the Kousakas’ alma mater.While an otaku and proud of it, even he is brought speechless to Sena’s "fantasies". However he is kind, helpful, and willing to work things out between his members. He was also responsible for starting the friendship between Kuroneko and Sena.
The voice of sanity in the Video Game Research Club, Kaede acts as an assistant to club president Gennosuke and as uke in many of Sena’s fantasies.Friendly and easy to approach, Kaede acts as the representative for the club during the club recruiting season.
Bridget is a Meruru cosplayer, specifically the character Dark Witch Alpha Omega. The reigning champion until unseated by Kanako, she slowly warms up to the winner despite the former’s flaws.Bridget eventually figures out Kyousuke & Kirino’s actual sibling relationship and has to clue in Kanako in Volume 11.
The second of the Gokou siblings, Hinata is at that age where she can appear cute and cuddly but can call out her older sister on her delusions & mistakes. When Kuroneko isn’t around she’ll be the one taking care of the youngest Gokou, Tamaki.Hinata is quite fond of Kyousuke (despite a bad first impression) and looks up to Kirino.
Model, designer, otaku and Kirino’s fake boyfriend. Kouki is polite and calm, even in trying situations. He’s also quite the pervert, as indicated when one enters his home.After the fake boyfriend incident, Kouki becomes friends with Kyousuke. He’s flattered when Kyousuke comes to him needing advice and does his best to help. However, he also likes to tease Kyousuke about his relationship with his sister and on occasion send him things to help encourage it, much to Kyousuke’s chargrin.Kouki is later introduced to the Game Research Club and gets along with them almost immediately. He is also introduced to Kouhei Akagi. Kouhei is quite disturbed, but still friendly with him.