Put rice in a large bowl. Rinse the rice and discard the water immediately. Rice absorbs water very quickly when you start washing, so don't let the rice absorb the unclear water. Repeat this process 1-2 times.

Now use your fingers to gently wash the rice by moving in a circular motion. Rinse and discard water. Repeat this process 3-4 times.

Let the rice soak in water for 30 minutes.

Transfer the rice into a sieve and drain completely.

Gently clean the dashi kombu with a damp cloth but leave the white powdery substances which contribute to the umami flavor in dashi. Do not wash the kombu.

Put the rice in the rice cooker bowl and add water (not hot or warm) to just under the 3 cup line. If your rice cooker has "Sushi" option, add water to 3 cup line for "Sushi". Since you add sushi vinegar to the rice, rice is on the firm side.

Place the kombu on top of the rice and start cooking.

In large pot, place the rice, the water and the kombu on top of the rice.

Place a lid on the pot, and place it over high heat. Let the pot come up to a boil, then turn the heat down to low. Let it simmer on low for 15 minutes, then turn the heat off. Let it sit, with the lid in place, for an additional 10 minutes.

combine rice vinegar, sugar, and salt in a small saucepan and bring it to a boil over medium high heat. Whisk until the sugar is completely dissolved. You can also put the ingredients in a microwave-safe bowl and microwave for 1 minute, or till sugar is dissolved. Set aside to let it cool.

When the rice is cooked, moisten sushi oke/hangiri (a round, flat-bottom wooden tub) or a large bowl with water so the rice will not stick. Transfer the cooked rice into the sushi oke and spread out evenly so the rice will cool faster. While it’s hot, pour sushi vinegar over the rice.

With a rice paddle, slice the rice at a 45 degree to separate the rice grains instead of mixing. At the same time you need to use a fan to cool rice so the rice will shine and doesn't get mushy.

Then gently flip the rice in between slices. Repeat this process till rice is cooled.

Keep the rice covered with a damp towel (or paper towel) until ready to use.