Koroshiya 1 THE ANIMATION: EPISODE 0

In the post-apocalyptic world that Earth has become in the 21st century, monsters, mutants, and demons all roam the land looking for human prey. Kakugo and Harara have been trained by their father in the ancient Zero fighting technique, to protect the last remnants of humanity, and restore hope and peace on Earth. Powered by both their superior fighting skills and their secret techniques, as well as special living armor made from the souls of ancient warriors, they are sent into the world to defend the weak from demons and mutants who savagely attack and destroy human life. Yet, with all their training, Harara succumbs to the evil within, killing their father and believing Kakugo is dead as well. But their fates are still intertwined. Kakugo comes to the remnants of a city to help the few human inhabitants. As he saves them from the ravages of cannibalistic monsters and depraved mutants, he once again encounters his psychotic sibling, and the bloodiest battle of the 21st century brings new meaning to Sibling Rivalry!

Ryou Matsumoto is a screenplay writer that runs into a man and witnesses his murder. Unknown to him, he gets caught up in an illegal antique ring along with a girl he meets named Yuki. In order to survive, he ends up acting out the "action hero" role that he writes in his screenplays.

Ten Years ago, Genichirou Izayoi died trying to stop the sorcerer Rebi Ra, and as a result Shinjuku became a playground for demons. And now, the day approaches when Rebi Ra will complete his decade-long ritual to plunge the rest of the world into chaos! As Genichirou's son, it falls to Kyouya to venture into the heart of Shinjuku and put an end to the sorcerer his father couldn't beat. Can Kyouya exceed his father's legacy, or will the demons of Shinjuku create Hell on Earth?

Long ago, there lived a young man named Yosuke in the village of Shiiba in Hyuuga. "I want enough money and possessions to live a luxurious life without having to work" Yohei abandoned his job in his impoverished village, where only barnyard millet, oxtail millet and beans could be grown. He fled into the mountains, where one night he witnessed a strange sight. A blue ogre clinging to a large cedar tree split its back, began to shed its skin and quickly transformed into a red ogre. Yosuke stole the shed skin, wore it and began committing crimes in the village. However, when he tried to take off the skin, he couldn't get it off no matter what he did...