Soak the whetstone in water for five minutes. Put the whetstone on a damp cloth after it is thoroughly wet.
Place the Shun bread knife on the wet whetstone with the blade at an angle of 45 degrees. Press the cutting edge of the blade on the whetstone with the fingers of your left hand so that the handle is held up and away from the stone with your right hand.
Move the blade up and down the face of the whetstone while keeping the knife at 45 degrees to the whetstone and holding the blade down with your fingers. Leave the muddy water formed on the whetstone while sharpening as this helps the sharpening process. Keep sharpening until burrs appear all over the length of the cutting edge of the Shun knife.
Flip over the Shun knife to its reverse side. Hold the knife on the whetstone at the same angle and with the blade held down and the handle held up. Slide the cutting edge of the Shun knife up and down the whetstone until burrs appear on the length of the knife.
Remove the burrs by lightly grinding both sides of the knife.