Marinate the Chicken:

Place chicken thighs in a large bowl or resealable plastic bag.

In a separate bowl, whisk together soy sauce, brown sugar, pineapple juice, garlic, and ginger until the sugar is fully dissolved.

Pour the marinade over the chicken, seal, and refrigerate for at least 4 hours, preferably overnight.

Prepare the Marinade for Basting:

Remove chicken from the marinade and set aside.

Pour the leftover marinade into a saucepan and heat over medium until it begins to simmer.

Let it cook for 5-10 minutes until slightly thickened.

Grill the Chicken:

Preheat your outdoor grill to medium-high heat.

Place the chicken thighs on the grill and baste with a portion of the cooked marinade.

Cook each side for 6-8 minutes, or until the internal temperature reads 165°F.

Rest and Serve:

Wrap the grilled chicken in foil and let rest for 5-10 minutes.

Serve whole or sliced with remaining hot teriyaki sauce poured on top.