Ichi the Killer: Episode 0 is an animated adaptation of the manga and was produced because of the popularity of the live-action film, it is a combonation of extreme violence and unemotional content, Kakihara still proves to be one of my all time favourite manga characters and I like all of Hideo Yamamoto's work so it's hard to pick a fav, but what makes it better is him being voiced my directing genius 'Takashi Miike'. More towards the plot of the film, it's centered in Ichi's past which was never shown in the manga, only snipets were shown in the manga, so it's more of a filler than anything else, but it'll be the best filler you'll ever see, I promise you that. But I wouldn't recommend this OVA unless you are a hardcore Ichi the Killer fan...