Ichiro Okouchi (大河内 一楼 Ōkouchi Ichirō), born on 28 March 1968 in Sendai, Miyagi Prefecture, is a script writer for the Azumanga Daioh anime and one of the people who played the biggest part in adapting the manga. He has written the script of ep. 1, ep. 2, ep. 3, ep. 4, ep. 5, ep. 8, ep. 12, ep. 15, ep. 20, ep. 24 (together with Aya Yoshinaga), and ep. 26. He is known for being a screenwriter and novelist, having written novels about Revolutionary Girl Utena among other things. He is a graduate of Waseda University, School of Human Sciences.
In 2006, Ōkouchi collaborated with director Gorō Taniguchi for composing the story and script of the Sunrise original production Code Geass: Lelouch of the Rebellion and its sequel, Code Geass: Lelouch of the Rebellion R2, in 2008. He has also written episodes for such anime series as Wolf's Rain and Negima!.