Christmas is a holiday for lovers
Even though Japan has a Valentin’s Day (in fact, they have two of them!), they also use Christmas as an opportunity to celebrate their love. You can take your date out on Christmas Eve, and on Christmas day, that’s when you engage in acts of love with the love of your life (cue romantic music).
So, if you’re in Japan during the holiday season, don’t expect to receive any gifts from friends or coworkers. In fact, if you do, it’s safe to assume that the person who gave you the gift is pretty into you. Also, don’t go acting as Santa Clause and handing out gifts, either, or you might end up in a bit of trouble.