Nakaimo: My Little Sister Is Among Them!

"Nakaimo: My Little Sister Is Among Them!" (Japanese: この中に1人、妹がいる！, Kono Naka ni Hitori, Imouto ga Iru!) is a Japanese light novel series written by Hajime Taguchi. The story follows Shogo Mikadono, who must find a life partner before graduating high school to inherit his father's company. However, he discovers that his long-lost younger sister is also attending the same school, and he has no idea who she is. This sets the stage for a romantic comedy with harem and mystery elements, as Shogo tries to navigate his romantic life while simultaneously trying to identify his sister. The light novel series has been adapted into a 12-episode anime series by Studio Gokumi, which aired in 2012, along with a special OVA episode. The anime was streamed on Crunchyroll and Anime Network and licensed by Sentai Filmworks.