Various methods can be used to create hair alpha maps, hair and fur, plug-ins and various other methods. Although for a low ply character in my opinion it is best to keep it simple by extrusion of the base head mesh and apply hair to it especially if it is going into an engine as a playable character and not for a cinematic inside the game engine or in a program such as Maya or Max for animation and export into the engine. However you can get creative with the way you create hair by adding accessories to the hair in this case two chopsticks in the bun of the hair, this is not regulation for military personal but it gives character to a other wise plain hairdo. This also helps when you do not want to use a lot of extra polys in game however, I will do a model with hair applied to geometry later which could be used for a cinematic or higher res character. Although this is a simple method for creating hair more realism can be added with alphas for certain areas around the head.