The Dark Signer outfit can be worn by both male and female characters in Yu-Gi-Oh! 5D's World Championship 2010: Reverse of Arcadia.
It can be purchased from Chihiro for 15 Star Chips after completing the main story mode. For males, it is a replica of Kalin's Dark Signer outfit. For females, it is a replica of Carly's Dark Signer outfit.
This set can also be found in Yu-Gi-Oh! 5D's World Championship 2011: Over the Nexus.