Nogizaka Haruka no Himitsu is set at the private high school Hakuj? Academy in Japan and centers around the male protagonist Y?to Ayase and his classmate Haruka Nogizaka. While Y?to is rather ordinary, Haruka is very attractive, intelligent, and rich. Due to this, she is the school’s most unattainable girl and is so idolized that her classmates give her the French nicknames “Nuit Étoile” (The Silver Star of the Night) and “Lumière du Clavier” (The Shining Princess on the Piano). One day, Y?to’s good friend Nobunaga Asakura asks him to return a book to the school library, and when he goes to return it, Y?to stumbles across Haruka and her darkest secret—she is a diehard fan of anime, manga, and the otaku culture. Y?to promises to keep her secret hidden and the two become close friends. Y?to does his best to help Haruka with her secret hobby while developing his relationship with her.