Japan has had as many as five thousand castles built, which is comparable to that of England and Wales on a per area basis. This is, of course, primarily due to the Sengoku era of feuding warlords, or daimyo.

Much of Japan's history had been dominated by a shogunate. Shogunates were the governments of shogun, derived from an old imperial title, sei-itai-shogun, which was the title given to warlords who conquered the "barbarians" (the Emishi people in the eastern and northern parts of what is now Japan). This Shogun typically ruled as the real power behind a figurehead emperor. However, at varying points in history, the shogunate grew weak as well. Regional lords often began to feud with each other, leading to the construction of these castles as a means for daimyo to defend and administer their areas of control. These castles were unlike European ones to an extent as the towers were often constructed of wood-which made them hideously vulnerable to fire. In fact, fire was such a threat that fish statues were put on the roofs of many castles as a sort of superstitious protection against fire (fish living in water, and water putting out fire, or something like that).

Many of these castles persisted until the 1800s, when after the Meiji Restoration, in an effort to preempt the creation of several feudal holdouts, all castles were ordered torn down by the Imperial government. In addition, the few that survived often suffered damage from US air raids during WWII. A notable survivor is Himeji Castle, where the castle wasn't torn down due to the owners being too impoverished to afford it, US bombs smashing a Japanese barracks on the site but missing the castle keep itself, and a dedicated Japanese attempt to preserve the remaining castles after the war. Even an earthquake failed to damage it, as Himeji had, like many other castles, been constructed on a semi-loose bed of large boulders tightly packed together. This gave it an element of resistance to earthquakes allowing the castle to remain unharmed.