The "perfect" girl who doesn't have any friends. She joins the Neighbor's Club.
The wealthy blonde daughter of the school's headteacher. Sena shows a dislike of all "ordinary" things. She is both attractive and academically successful, but her arrogance leads her to be disliked by her female peers. She treats her male classmates as servants to be used, although many of them would like to be her boyfriend. She holds Kodaka to a higher standard. Kodaka concludes that she is the weirdest member of the club, because she is able to warrant weird and disgusted looks not only from Yozora and Kobato, but also from Yukimura and Rika.
She enjoys playing video games, including dating sims and eroge, partially because then she can make female friends. She is fascinated by the girls in these games and has also taken a liking to Kobato. Yozora calls her "Meat" (Niku, due to her large breasts). An insulting nickname which she secretly likes because it was the first nickname she received.