Ichirō Ōkouchi is a Japanese screenwriter and novelist. He is a graduate of the School of Human Sciences in Waseda University. Ōkouchi is best known for collaborating with director Gorō Taniguchi for composing the story and script of the Sunrise original production, Code Geass: Lelouch of the Rebellion in 2006 and its sequel Code Geass: Lelouch of the Rebellion R2 in 2008.