Kyosuke is the 17-year-old main character of Oreimo. He has a distant relationship with his sister, feeling that this will never change. However, this suddenly changes when he finds one of her eroge and after he confronts her, he learns that she is an otaku. Through this, he tries to be a supportive older brother while realizing he himself knew very little about his sister, such as being almost flawless at school to working as a model. After which, he promises to take up more of his role as an older brother to her. Despite this, she is generally the dominant person in their relationship, with Kyosuke being shown to be openly intimidated by her, only standing up to her in truly serious situations