KFC is successful in Japan because they invented the tradition of eating KFC fried chicken during Christmas.

No joke, Christmas bookings for KFC are booked out months in advance, and people wait in long queues out the door on Christmas.

What's the deal with KFC and Christmas in Japan? | Time Out Tokyo - https://www.timeout.com/tokyo/things-to-do/whats-the-deal-with-kfc-and-christmas-in-japan