According to the show page and other websites this was inspired by anime. I can see that by the style but it has none of the other things that would expressly make it an anime. You could argue that the violence and gore is one but violence and gore are not exclusive to Japan or anime. Metalocalypse and Superjail are two animated shows that have tons of blood, gore and violence and they're American. So are we going to start seeing some sweat drops or something? Otherwise I'm not really seeing the "anime" inspiration.
So this is an anime?
About Mari - Kari
Mari and Kari are identical twins. They’re best friends and never apart. Mari is the liveliest girl you’ll ever meet. Kari is too. Her problem: she’s dead. From there it gets weird.