Crock Pot Teriyaki Chicken

6 boneless skinless chicken thighs (about 1.5 pounds)
1/4 cup sugar
1/4 cup soy sauce
3 tablespoons cider vinegar
1/4 teaspoon ground ginger
1/4 teaspoon minced garlic
1/8 teaspoon pepper
2 1/2 teaspoons cornstarch
2 1/2 teaspoons cold water
Cooked long grain rice
Place chicken in a 4 qt. slow cooker. 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 thickend. Serve with chicken and rice.