Like many other non-Christian countries, Japan has got into the habit of celebrating Christmas.
But as well as the usual decorations and presents, the Japanese have also made this season into an uniquely romantic one.
For the country's famous Love Hotels - fantastic-looking roadside buildings which beckon travellers with flashes of neon - this is by far their busiest time of year.
Guests pay according to how many hours they stay
Christmas Eve has, for reasons no-one has been able to explain to me, become the most romantic night of the calendar.
At a time when many Christians are in church, it has become a tradition for young couples to enjoy their first moments of passion; for suitors to propose marriage; for older couples to escape the noisy confines of the family home for a rare night of intimacy.
Ideally, this should happen in a luxury hotel. But these are booked up months in advance, and are beyond the pockets of many Japanese.
The alternative is a Love Hotel. With beguiling names like the Hotel Seeds, Hotel Carrot and Hotel Be Free, they offer guests rates for what is called "rest" - two to four hours - or "stay" - in other words overnight.
Inside you are spared the embarrassment of checking in. You simply punch the room you want on a panel of buttons and you are given a key card, which you insert at the end of your stay to pay the bill.
The rooms themselves can have astonishing decorations. The bed might be a full-size 1950s Cadillac car. Some rooms have illuminated displays on the walls and ceiling that make it feel like you are under the sea. Some have Hello Kitty dolls in leather underwear and handcuffs.
However strange your preferred theme, there will be a Love Hotel somewhere for you. The only disadvantage is you cannot book these hotels in advance.
Which means on Christmas Eve, you might have to queue in the cold and unromantic street before you get a room.