It’s a question that many Westerners have asked for decades: How did Christmas in Japan become synonymous with a fast food joint?

Foreigners may laugh at the queues that form outside branches of KFC on Dec 24, or the people reserving their buckets of chicken months in advance, but it turns out that they’ve only got themselves to blame.

The tradition of eating KFC at Christmas dates back to the early 1970s, when an expat customer at the chain’s Aoyama store observed that, in a land bereft of Yuletide turkey, fried chicken was the next best thing. The store’s canny manager was paying attention and passed word on to the higher-ups, leading the company to launch its ludicrously successful “Kurisumasu ni wa kentakkii!” (Kentucky for Christmas!) campaign in 1974.

At least, that’s what the company says on its website (www.kfc.co.jp/qa).

Or it might just be because Colonel Sanders looks like Santa Claus.

Whatever the reason, chicken is big business for KFC in December. Actress Haruka Ayase, 26, who appears in TV commercials and other ad campaigns for KFC, helped the fast-food company launch its Christmas campaign in late October, by promoting reservations for the KFC Party Barrel.

Company officials say KFC records its highest sales volume each year on Christmas eve. The stores are so busy that even back office staff, including the president and other execs, head out to the frontlines to help on Christmas eve.