The then-19-year-old Isayama submitted the manga to Kodansha’s Magazine Grand Prix contest in 2006, and it won the “Fine Work” award.
Kodansha’s Magazine Debut website published Hajime Isayama’s “Jinrui VS Kyojin” (Humanity vs. Giants or Humanity vs. Titan) one-shot manga on November 1.
The manga has inspired three anime series since April 2013 — the second part of the third season will debut in April 2019.
Before that, he had submitted the manga to Shueisha’s Weekly Shonen Jump magazine, but was rejected.