Some of the female characters in Dead or Alive 5 (DOA 5) for the PS3 and Xbox 360 have alternate panties that can be selected.
To select different panties, do the following:
On the costume select screen, highlight a female character then press and hold any Hold, Punch, or Kick button.
Check out my other article for a complete list of unlockables, cheats, tips, and tricks for Dead or Alive 5.