Sumo has been around in organized form for over 250 years. As a sport in which the rankings and most of the promotion/demotion rules and regulations have remained unchanged, sumo has just turned 100.
Yet, and as has been covered in Sumo Scribblings before, the sport is more than just a sport — for sumo is as culturally ingrained in the Japanese psyche as any other so called "sport" in just about any other nation on earth.
As quintessentially Japanese as sumo is, however, over the years, it has gradually opened up to outside influence. Perhaps not quite as fast as some would like — particularly for fans overseas — but the sport has advanced in leaps and bounds, especially in the decades since World War II. Rikishi from around the world have enjoyed the same opportunities as their domestic counterparts to advance to the top of the ranking structure in the sport, with only two "supposedly" real examples of note on the subject of discrimination preventing promotion for non-Japanese. Unfortunately these two examples are an ever-present in the minds of many foreign fans, many of whom hold their own, usually Western, sociocultural norms up as measuring sticks to Japanese sumo thanks to the Internet and ease of global communication in doing so.