Cooking rice in a Japanese rice cooker is very simple once you know the basics. Make sure you get these three steps right and you'll have delicious, perfectly cooked rice from your rice cooker.
How to cook perfect rice
- Rinse
Short grain white rice (the most common variety in Japan) should be rinsed before cooking, so quickly rinse and renew the water 3 times. - Add water
Next add water to the cooker bowl. White rice and water should be in a 1:1 ratio - if you put in two cups* or rice, add two cups of water.
Alternatively, if you put in two cups of rice, fill the cooker bowl with water up to the 2 under the 白米（はくまい/hakumai） mark. Rice cooker bowls generally have this marking on both sides of the bowl (on the inside). - Set cooker
Then put the bowl in your cooker and, with the cooker set to normal settings (short-grain, white) rice - 白米 - press the big red 炊飯（すいはん/suihan） start button and wait for the chime.
*Make sure you use the cup that came with your rice cooker. Cups for measuring rice are usually about 180mL.
How long does it take?
Cooking 3 cups of rice in a rice cooker takes about 45 minutes on normal settings.
If you want a slightly faster cooking time, find the settings with the kanji for fast - 早. It may say 早炊き（はやだき/hayadaki）, and this is the fast cook mode.
Note: there are generally two big buttons on a rice cooker. One is for the 'keep it warm' option and the other one is the 'cook' option. On my machine, these buttons are, respectively, orange and red and say 保温（ほおん/ho-on） and 炊飯（すいはん/suihann）｜おこげ(okoge).
A Japanese rice cooker
This is a nice demonstrative video but I do have one criticism to make and that is that you shouldn't wash 5 or 6 times as suggested. For the best rice, wash it three times only and leave the water just a bit misty with the white starch.