Do I need authorization to create a Doujin cosplay costume?

Creating a Doujin cosplay costume usually didn't require authorization because Doujin works referred to the re-creation of an original work, including cosplay costumes. However, if the cosplay costume was based on an illegal original work (such as a copyright-violating comic, novel, game, etc.), it would need to be authorized by the original work. When creating a Doujin cosplay costume, you can choose to create it yourself or purchase the original copyright. Self-creation required copyright considerations and permission from the original owner. Purchasing a license would ensure that the work would not violate the copyright of the original owner and would be paid accordingly. It should be noted that if the cosplay costume is based on an illegal original work, even if it is authorized, it may face legal risks. Therefore, it is recommended to understand the relevant laws and regulations before making a Doujinshi cosplay costume and choose a legal original work to create.