Hajime Isayama broke into the manga industry in 2006 when he applied for the Magazine Grand Prix promoted by Kodansha Ltd. with a short version of 
Attack on Titan. The short received an award and inspired him to move to Tokyo at the age of twenty. In 2009, his first serial work, 
Attack on Titan, started in 
Bessatsu Shōnen Magazine. It won the Shōnen category of the 35th Kodansha Manga Award in 2011, and was nominated for both the 4th annual Manga Taishō Award and the 16th annual Tezuka Osamu Cultural Prize. 
Hiroshi Seko is a Japanese writer best known for creating the story for the manga 
Attack on Titan: Lost Girls. Among his TV writing credits are 
Attack on Titan, Kill la Kill, and 
Panty & Stocking with Garterbelt. Seko also did series composition for 
Seraph of the End and 
Mob Psycho 100.