In a large bowl, combine the sugar, soy sauce, cider vinegar, ginger, garlic and pepper. Pour over chicken. Cover and cook on low for 4 to 5 hours or until chicken is tender.
Remove chicken to a serving platter; keep warm. Skim fat from cooking liquid. Place liquid in a saucepan and bring to a boil. Combine cornstarch and water until smooth. Gradually stir into liquid and stir until sauce is thickened. Serve with chicken and rice.