According to several sources, including the Gurumin Wiki, I can obtain a Santa outfit by playing the game between December 25 and December 31.
I loaded my original North American UMD copy of Gurumin: A Monstrous Adventure into my PSP, verified that my system date and time were set correctly to December 25, 2023 at about 11 AM, loaded my save game, and checked my clothes closet. I was offered the opportunity to change, but all of the options show "Change into ????" and none of them actually change my character's clothes when I click on them. I have tried visiting Monster Village, entering the monster world, completing a stage, returning home, saving my game, restarting the game, and reloading from that save file, and the behavior does not change.
How do I actually claim or unlock the Santa outfit? I do know that there are several versions of the game on different platforms. I am playing my North American physical UMD copy on my PSP-2001.
