Residents of Pokemon Square have been more than familiar with the human customs, the one that caught their interest the most being the event they seem to call "Christmas". Not just the story behind it, but how it's celebrated as well, sharing gifts, bringing people together...so eventually, they decided they should celebrate it as well!
However, instead of celebrating birth of a messiah from legends and cutting down a random tree in the wild so that various decorations can be placed on it, residents of Pokemon Square would all gather around a randomly selected tree in the forest, decorate it and spend the night exchanging presents, dancing, singing, just spreading the holiday cheer to their fellow Pokemon, family and friends alike. For this one night there were no ill feelings or rivalries; everyone was unified in the spirit of the holiday.
As this was the first Christmas he would spend with Carmela, Ricky went to great lengths to make sure he picked a right present for her, despite her constantly insisting the greatest gift she could ever receive is his friendship.