Place the rice, water and the piece of Konbu in the rice cooker.
Make the rice as per instructions on the rice package or tice cooker.
Prepare the rice vinegar mixture, as the rice cooks.
Once the rice is cooked, have a large bowl ready.
Place the rice in the bowl, and using wooden spoon or rice server, slice sideways through the rice as you pour in the rice vinegar mixture. See the top photo inthis blog.
The difficult part is fanning the rice as you pour on the mixture is it takes two persons. But if you are solo, fan the rice immediately after you mix it with the vinegar.
Once done, you can place in containers in the refrigerator, or freeze and vacuum pack.