Attack on Titan: INSIDE Kou (進撃の巨人 INSIDE 抗 Shingeki no Kyojin INSIDE Kou?) is the first of three official guidebooks for the Attack on Titan manga, written and illustrated by Hajime Isayama. It is 192 pages long and written entirely in Japanese. An English version called Attack on Titan Guidebook, which combined Attack on Titan: INSIDE Kou and Attack on Titan: OUTSIDE Osamu, was released in North America on September 16, 2014 by Kodansha USA.