Authoring, ie portrayed characters and their surroundings do not belong to any product (anime, movie, game), and is entirely an invention of the artist. pixiv fantasia: Pixiv Fantasia is a joint project on Pixiv to create a fantasy world. The basic plot (according to a Google search, anyway) is that there is a world that has been invaded by the "Calamity". The world is made up of 5 kingdoms, each with its own unique characteristics. Pixiv users then fleshed out this world by submitting illustrations and descriptions of heroes and monsters. long hair:
Length is shorter than shoulder length, but no longer than the knee. single:
Images depicting only one character.
No one else should be visible in the picture.