In a mixing bowl, whisk together soy sauce, brown sugar, honey, minced garlic, grated ginger, sesame oil, rice vinegar, and gochujang until the sugar is dissolved and the marinade is well combined.

Place the chicken thighs in a large resealable plastic bag or a shallow dish and pour the marinade over the chicken. Ensure all pieces are coated evenly.

Seal the bag or cover the dish and refrigerate to marinate for at least 1 hour, or preferably overnight for deeper flavor.

Preheat your grill to medium-high heat.

Remove the chicken from the marinade, letting any excess drip off. Discard the remaining marinade.

Grill the chicken for 6-7 minutes on each side, or until the internal temperature reaches 165°F and the outside is nicely charred.

Transfer the grilled chicken to a plate and let it rest for a few minutes.

Garnish with sesame seeds and sliced green onions before serving.