Doujin novels (also known as "second creation novels","doujin manga, novels, games, etc.") referred to literary works that were re-created, continued, or adapted by other authors or creative teams based on an original character, work, or IP. These works usually involved the original character or IP's worldview, character, plot, etc. There were certain similarities with the original work, but they often added their own creativity and imagination to create a unique storyline and character image. Doujin novels were usually created based on the love and passion for the character or IP, as well as the understanding and imagination of the world and storyline. As such, Doujin novels had a variety of styles and content. They could be about romance, science fiction, history, fantasy, and many more. Doujin novels were very popular on the internet, especially in the fields of games, animation, and manga.