Monsters Club(モンスターズクラブ)

Having abandoned modern civilization, Ryoichi lives an isolated, self-sufficient life on a snow-covered mountain and sends mail bombs to the CEOs of corporations and TV networks. One day, he encounters a mysterious creature in the forest. That night, his older brother, who had committed suicide, appears before him at his cabin. The apparition takes Ryoichi beyond a door, where Ryoichi learns the truth about his family.