Doujin novels (also known as "second creation novels","fan-created novels", etc.) referred to novels that were based on the story, characters, and worldviews of an original work (usually anime, manga, game, novel, etc.). They were usually created by fans or fans of the original work or continued by some professional novel creators. Doujinshi novels were usually created by re-conceiving and deducing the original characters, plots, backgrounds, and other elements to create their own unique storyline and characters. Doujin novels are closely related to the original work because they are based on the original work. Some Doujin novels even have a close relationship with the original work to produce "Original God Doujin novels" and other similar works. Doujinshi was widely used in fan culture. Many fans liked to express their feelings and thoughts through Doujinshi, and at the same time, it could let more people understand and like the original work.