Wash Japanese rice well and drain. Put water and rice in a pan. (*an earthenware pot is suitable.) Leave it for 30 minutes. Put the pan on medium heat and bring to boil. Turn down the heat and cook the rice for 30-40 minutes. Add salt before serving. Sprinkle chopped green onion and sesame seeds if you wish.
This is a recipe to make plain okayu. You might want to add some vegetables or meat, depending on your appetite.