Nagisa Furukawa (古河渚, Furukawa Nagisa?), later Nagisa Okazaki (岡崎渚, Okazaki Nagisa?), is the main female protagonist of Clannad. She is the daughter of Akio and Sanae Furukawa and appears as both the female lead and the main love interest of protagonist Tomoya Okazaki throughout the Clannad visual novel and anime, Nagisa becomes an even greater force in the story during the ~After Story~ arc, culminating in her marriage to Tomoya and the birth of their daughter, Ushio.
Named for her, Nagisa's theme song is Nagisa.