Doujinshi are self-published works, often in the form of manga, novels, or art books, created by fans or independent artists. They typically feature original stories or characters, but can also include fan-made content based on existing franchises, such as anime or video games. These works are usually sold at conventions, online, or through specialized shops. Doujinshi culture is particularly popular in Japan, where creators can express their creativity and connect with like-minded fans. The community surrounding doujinshi encourages collaboration and sharing, fostering a vibrant artistic environment.