Manga are Japanese comic books that originated in the 18th century. Anime are animated adaptations of manga stories. Dojinshi are fan-made manga and stories. Manga became popular in North America in the late 20th century and is now a $180 million industry there. Anime and manga works are categorized by their target demographic audience such as shonen for young boys or shoujo for young girls. They also have genre categories including action, horror, romance, and mecha involving robots.