Captain Hero

Captain Hero is a series of comics that dates at least from when All For One and his younger brother Yoichi Shigaraki were children.

Overview
Captain Hero is a series of comics that tells the adventures of the titular protagonist against the Demon Lord. At some point in the story, the main villain manages to take over the world, but Captain Hero struggled to past the pain and in the end he managed to defeat his nemesis and save everyone.

As children, All For One and his brother Yoichi enjoyed reading the comics together. Yoichi was a fan of Captain Hero while All For One was a fan of Captain Hero's nemesis, the Demon King. While his younger brother read the entire comic series, which ends with the villain's defeat at the hands of the hero, All For One read only to Volume 3 of the series, but stopped because he didn't like the cliched ending between "Hero" and "Villain".

The comic had a strong influence on the ideology of the two brothers. All For One dreams of being a demon king and creating a world just like the comics. While Yoichi, fought for justice just like Captain Hero, trying to stop his older brother.