In a mixing bowl, combine the pineapple juice, brown sugar, ketchup, soy sauce, ginger, and garlic. Whisk until thoroughly mixed.

Place the chicken pieces into a large resealable plastic bag. Pour the marinade over the chicken, ensuring all pieces are well-coated.

Seal the bag and refrigerate for at least 4 hours, or preferably overnight, to allow the flavors to meld.

Preheat your grill to medium-high heat.

Remove the chicken from the refrigerator and discard the marinade.

Grill the chicken for 6-8 minutes on each side, or until the internal temperature reaches 165°F.