Curry Rice in Japan : Extra Topping Matters.

"Curry rice" （カレーライス） originates in India but it has been loved for decades in Japan as well. Traditional curry rice among Japanese consists of steamed rice with viscous curry sauce covering boiled beef, pork or chicken and can be enjoyed at curry restaurants, ramen restaurants, beef bowl restaurants, and is actually also available at convinience stores.

When you have curry rice at curry restaurants, don't forget to try some extra toppings such as a boiled egg, cheese, vegetables and hamburger. Especially hungry guys and gals can order a couple of toppings on one plate. The most popular topping is pork cutlet. Known in Japan as "Katsu-curry"（カツカレー）, this delicious meal can be ordered at various kinds of restaurants that have curry rice on the menu.

"Curry House CoCo Ichibanya"(カレーハウスCoCo壱番屋) operates the most curry restaurants throughout Japan and in fact, has more than 1200 locations. At "Koko-ichi" restaurants, you can choose rice size and spice level as well as select from an extensive palate of extra toppings.
http://www.ichibanya.co.jp/index.html

If you want to know further information in English, you can refer to their global site. Although the global site provides contents about the chains outside Japan, the international menu is not really much different than what is offered in Japan.
http://www.ichibanyausa.com/index.html

"Go! Go! Curry"（ゴーゴーカレー）, a growing chain from Kanazawa, is also increasingly popular. However, still limited in size, they operate just about 30 restaurants in Tokyo. If you are lucky enough to come across one during your stay, do not hesitate to try it. I am sure it will give you something else special about Japan to remember.
http://www.gogocurry.com/