Curry powder was introduced to Japan from India (via the British) by the mid 19th century. It immediately caught on. Originally considered a Western dish (British Navy curry), Japanese curry was adapted to local tastes with time.
It is considerably blander than a typical Indian curry. Westerners might compare it to a spicy gravy. Spicier variations are available but are typically a disappointment for spicy food enthusiasts.
Japanese curry has a thick texture and is usually served with vegetables and meat. Vegetarian curries are relatively rare in Japan.
Vegetables are usually of the basic variety (onions, carrots and potatoes). Beef and pork are the most common meats used. Beef is popular in Osaka and pork in Tokyo.
Japanese short grain rice is the preferred rice for curry in Japan.