As a student, Kirino possesses a keen focus to studying and athletics. This attitude of hers when it comes to school activities has rewarded her with above-average marks, even as she enters the career of modeling. She developed a sort of perfectionist attitude due to becoming an overachiever, which eventually made her more prone to struggling when the odds are against her. When these moments come, however, she displays a more passive side.

During her initial interactions with Kyousuke, she demonstrates an attitude similar to a "tsundere", with the bossy and abusive part more dominant. Although she maintains this attitude, she slowly tries to open up to her brother at times, reluctantly expressing gratitude on things that Kyousuke has done for her. It is later clarified that she does care for Kyousuke, although she chooses indirect methods, sometimes laced with her sharp tongue, to show her sisterly affection for him

She has a strong "little sister" fetish and owns many adult games with older brother/little sister themes, which is paid by her salary for modeling. Despite this, she insists that she does not know why she started liking it, though it is suggested that she has a brother complex and is using the games as a surrogate to this. She often denies such feelings and believes the 2D and 3D worlds should be kept separate. Aside from this, she is also an avid fan ofStardusto Witch Meruru and any series with cute themes in general.

Kirino is a third-year student of an unnamed middle school in Chiba. She is known not only for her above-average grades, but also for her athletic prowess in track and field. Aside from living a life as a student, she is also a part-time model for various fashion magazines, which is her main source of pocket money to sate her hunger for anime merchandise.

According to Kyousuke, his relationship with Kirino was much more positive in the past. However, due to a series of events, she changed her interactions with him. By the start of the series, the two have been living with minimal interaction between each other.

PlotEdit

Kirino's Secret LifeEdit

Kirino has been used to treating Kyousuke rudely, especially with Kyousuke often acting unfriendly or indifferent at home. In one of her trips outside, she drops a DVD case of Stardust Witch Meruru on the Kousaka Residence's doorstep. Kyousuke ends up finding the DVD case and takes it to his room, where upon investigating who the owner of the DVD case is, concludes that Kirino is the owner of the DVD. To his shock, it actually contains an eroge entitled Let's Make Love With Little Sister!. Kirino later confronts Kyousuke in his own bedroom, and in the pretense of "life consultation" invites her older brother into her bedroom.

After confirming that she is the owner of the DVD case found earlier, Kirino also shows him a part of her hobby by letting him play one of her eroge in secret. This would mark the start of Kirino's constant provision of eroge for Kyousuke to play, as well as the beginning of Kyousuke's interaction with Kirino's secret hobby.

With Kyousuke's advice, Kirino jumps in to the online world of otaku communities and reluctantly joins a social networking service group called "Otaku Girls Unite!" under the handle name kiririn. Shortly, the group's moderator named Saori welcomes her to the group and invites her to a scheduled ofukai (offline meeting) with the other members of the group, to take place in Akihabara.

Kirino accepts the invitation and attends the ofukai with Kyousuke tagging along as her "backup" from a distance. She soon discovers that she finds it difficult to mingle with total strangers, and the only one who was able to console her after this ofukai was Kyousuke himself. However, Saori soon invites the two, along with another member who goes by the alias Kuroneko, to an afterparty in a nearby fastfood restaurant, followed by a trip across Akihabara before parting ways. Kirino refuses to admit that she had found friends in Saori and Kuroneko, although Kyousuke is certain that the trip wasn't for nothing in the end.

Challenges to the Status QuoEdit

After the events at the Otaku Girls Unite! social group, Kirino began to join Saori and Kuroneko in trips across Akihabara, although her relationship with Kuroneko is still shaky due to their divergent tastes in anime. After the two try to desperately make each other fans of the anime series they like, Kirino heads back home, only to discover that her secret hobby as an otaku has been exposed by her strict father, who shows an intense distaste in otaku culture.

Kirino storms out of the house after this confrontation, and she decides to stay over at a friend's house while Kyousuke assures her that he would do something about this issue. True enough, Kyousuke bet his own reputation by defending Kirino's hobby and lying about the eroge, calling it his. Kirino later returned back home when the situation has lulled down, and she thanks Kyousuke for his efforts, calling him "Aniki" for the first time.

During Summer Comiket, however, another threat to her hobby enters when her friend Ayase Aragaki, who is also a part-time model just like her, finds out about her hobby and swiftly declares the end to their friendship. As Kirino begins to worry about how much time is left before Ayase would reveal her hobby to everyone, Kyousuke helps him out once again by clearing Ayase's doubts about anime fans and the otaku culture and again putting his name on the line for the sake of his younger sister. The plan worked as Ayase threw away her doubts just to keep Kirino from being harassed by Kyousuke, in exchange for Kyousuke's name being tarnished by making the image of a siscon in Ayase's eyes.

Kirino's New CareersEdit

The Fateful Trip to AmericaEdit

Though delayed, Kirino eventually decides to go to America to pursue Track and Field.