Combine sugar, soy sauce, and water in an 8-quart pot; stir until sugar is dissolved. Turn heat to medium-high; add ginger, garlic, cinnamon, and black pepper and stir.
Bring mixture to a boil and add chicken drumettes. Once mixture begins to boil again, reduce heat to medium-low, and partially cover pot with a lid tilted to allow steam to escape. Simmer until chicken is no longer pink in the center and teriyaki sauce is thickened, at least 1 hour.