ochazuke is rice, tea and a lot of very Japanese stuff.
Ochazuke combines two quintessentially Japanese ingredients, plain white rice and green tea. Ochazuke is commonly served at the very end of an elaborate Japanese full course meal. It's also favored as a midnight snack, a hangover cure, or just when you want something hot and filling. It's commonly made with leftover rice, though ideally the rice should be heated up if it's cold.
The stuff that goes on top makes it flavorful. Nowadays most people use ready-made ochazuke packets, from companies like Yamamotoyama. These come in flavors such as pickled plum, salmon, wasabi and sea urchin. If you can't get a hold of such packets, here is a recipe of sorts. It's basically about rice, tea and "stuff" on top. Despite the fact that this is a make-in-a-minute kind of thing, the very Japanese-ness of the "stuff" that goes on top makes authentic ochazuke a rather difficult dish to assemble outside of Japan, unless you have a Japanese food store nearby.
For one serving
Put the rice in a bowl, Put on the toppings, and add a bit of salt to taste. Pour over hot green tea.