Miyabi Kannagi (神凪 雅/Kannagi Miyabi) is one of the heroines of the Kono Naka ni Hitori, Imouto ga Iru! series.
Miyabi is a petite girl for her age, which sometime could be mistaken as a junior high student. She has brown hair with long bangs and a fringe and also is usually tied with pig tails held by orange bows with light orange pom-pom balls hanging off them.
Like most characters she is usually wearing the school uniform with her top shirt button undone with her bow quite loose as compared to other characters. She also sometimes has her shirt untucked which overall gives her an rebellious and edge.
She was especially conscious of her small breasts, and appeared to be envious of Konoe's endowed body.
Miyabi childish look is evenly matched by her childish personality. She is lousy, energetic, and can quickly change her mood. Around Shougo, these characteristics are amplified, and Miyabi acts like his clingy little sister.
However, Miyabi was not always this way. As Konoe revealed to Shougo, on her first year at the Miryuin Academy, Miyabi secluded herself from her class and almost never interact with anyone else.
Like Konoe, Miyabi is very possessive of Shougo and will become jealous if she perceive any potential rival for his affection. However, ultimately she is concern about his happiness and will do anything, even ignoring her feeling, if Shougo is happy.
Another classmate of Shogo and a member of the swimming club. Miyabi revealed that she met Shogo at the hospital where he was recovering from his accident—whenever her father went in for treatments, she would play outside with him. When Shogo first attempted to speak to her upon meeting her in class, she refused to talk to him. After that, she overheard his conversation with Konoe and after seeing them almost kiss, demands that he kiss her. She reasons that after Shogo calls Konoe "just a classmate," it should be fine for him to kiss her as well. When she tells Shogo of their previous relationship together, she also confesses (with Konoe present) that she fell in love with Shogo as a child and along with Konoe was elated upon learning of his transfer to their school. She is competitive with Konoe about wanting to marry Shogo, to the point where they will argue about it in front of him. As the story progresses, she often interrupts romantic moments between Shogo and Konoe. At the end of the anime and in of the novel, she is revealed be his sister. And her so called "father" was actually a friend of her real father payed to take care of her. She then begins to act really protect over her brother and hosts a game to see who his proper mate should be which it is inferred that Konoe and Shougo would eventually become husband and wife.