Place the rice in an electric rice cooker or large saucepan. Add the remaining soy sauce and sake, and salt. Place the piece of kelp on top. Add water and cook according to rice cooker directions or, if using a saucepan, until the water is fully absorbed. When the rice is done, remove kelp, add the chicken and vegetables and stir well. Cover and let sit a further 10 minutes before serving.
*If using canned or precooked peeled bamboo shoots, drain and rinse them thoroughly in cold water before preparation. If the shoots are fresh, cut off the hard bottom part and boil them in their husks – water left over from washing rice or rice bran is best for this – with a dried red pepper for about one and a half hours to remove bitterness. Let cool, then peel off the husks. Wash well in cold water and continue with recipe preparation.