The Japanese culture is generally permissive with regard to the appropriation of ideas. Works such as dōjinshi, unauthorized comics continuing the story of an official comic series, are actually encouraged by many anime makers. These dōjinshi take an original copyrighted work and expand upon the story, allowing the characters to continue on after, before, or during the original story. Most anime producers encourage this practice, as it expands their series. Some see it as a tribute while others see it from a business viewpoint that it draws in more support for the anime than it would have had otherwise. Some manga artists create their own dōjinshi, such as Maki Murakami's "circle" Crocodile Ave ("Gravitation").