Place sugar, ginger, sake, and soy sauce in sauce pan and warm. Stir till dissolved, do not boil.
Place mustard in small serving dish and add enough water to prepare to desired paste.
May be used to marinate cooked bite size beef, chicken, or pork leftovers or freshly cooked meat. Marinate for at least 6 hours in refrigerator, overnight is better. Serve heated sauce and meat with toothpicks take meat and touch mustard and enjoy.