Japan is the only country in the world to still have a ruling emperor. In fact, the imperial line is said to have descended from the sun goddess Ameterasu over 2600 years ago in 660 BC. Even though there are some doubts that the imperial line began that early, it has been conclusively dated back over 1500 years, making it the world's oldest continuous hereditary monarchy. The current Emperor’s name is Akihito though Japanese people usually call him by generic titles that translate to things like 'His Majesty the Emperor' or 'His Current Majesty'. He resides in the Imperial Palace which is located in the center of Tokyo although for most of Japan's history the Emperor resided in Kyoto (which was also the capital of Japan back then).
According to the current law, when he dies, the emperor is succeeded by his oldest son. There were some female emperors in the past but current laws prohibit a daughter from taking the throne. Although there was some debate about that not too long ago when it looked like a mail heir might not be born.
Throughout history, the role and power of the emperor has varied considerably (ranging from pretty much total control of the government and army to virtually no control at all). For a lengthy period of time the emperor was nothing but a puppet for the Shogun (military commander). In fact, it was a Shogun who first moved the heart of Japanese government to Tokyo, leaving the emperor behind in Kyoto to show that he longer had an important role in running the country.
Power was restored to the emperor during the Meiji revolution (a reaction to the then current Shogun’s failure to keep Perry’s fleet out of Japan) though the Meiji Emperor relinquished much of that power to form Japan’s first democratic government in 1890 and the emperor’s power was further reduced after World War II. These days, the emperor has no real power and serves more as a figurehead than a politician.
While you can tour the old imperial palace in Kyoto (which I’ll probably talk about more in-depth in a future post), the palace in Tokyo is off limits except on the emperor’s birthday and a day or two right after new year’s, when the public is allowed to gather in one of the place’s courtyards to listen to an address from the emperor. The rest of the year, the best you can do is follow the moat around the perimeter, which passes through some nice gardens offers a few glimpses of the palace buildings.
Despite his lack of power, the emperor remains a very important figure to the Japanese people, serving as a role model and a symbol of the country’s long history and ancient traditions, much as England’s monarchy and may very well continue to do so for centuries to come.