It may be true that Kentaro is more relaxed around Christmas time, and may have fattened up a little, but don't think he's completely out of shape. One good feel of his "extra padding" make it clear that his muscles are still under there. While Millie may tease him a bit, she doesn't mind having him in this more huggable state for a few days. Once Christmas is over, he'll be working extra hard to get back in shape before new years. Luckily, there are plenty of people he knows who can help. That being said, he'll be careful not to neglect himself around the holidays in the future.