Rinse the rice several times in water until the water runs almost clear. I like to rinse the rice directly in the rice cooker pot - one less thing to wash!
Fill the rice cooker pot with water up to the “2 cup” line.
Add soy sauce and sake (optional) to the rice cooker pot. No need to stir or mix.
Cook the rice as you normally would in the rice cooker. There should be an automatic button setting on the rice cooker.
After the rice is done cooking, let sit for 10 minutes.
Open and drain the canned tuna. Add the tuna to the cooked rice.
Then add the shio kombu and green onions to the rice.
Use a rice paddle to gently mix everything together. Serve hot. Eat and enjoy!