The sailor uniform is an item of clothing in some video games. It can only be worn by female characters. The male alternative is the stuffed collar uniform.
In Yu-Gi-Oh! 5D's World Championship 2009: Stardust Accelerator, it can be unlocked by unlocking all Tag opponents in World Championship Mode.
Reverse of Arcadia
In Yu-Gi-Oh! 5D's World Championship 2010: Reverse of Arcadia, it can be found in the puzzle room of Zeman's castle.