In a small bowl, whisk together the teriyaki sauce, brown sugar, soy sauce, sesame oil, minced garlic, and grated ginger. This is your marinade.
Place the chicken cubes in a resealable bag or bowl. Pour about half of the teriyaki marinade over the chicken, ensuring it's well coated. Marinate for at least 30 minutes in the refrigerator, or up to 2 hours for more flavor.
While the chicken is marinating, thread the marinated chicken cubes, pineapple chunks, red onion chunks, and bell pepper chunks onto skewers, alternating the ingredients. If using wooden skewers, soak them in water for at least 30 minutes beforehand to prevent burning.
Preheat your grill to medium-high heat.
Grill the kabobs for about 10-15 minutes, turning occasionally, until the chicken is cooked through and slightly charred, and the vegetables are tender-crisp. Baste the kabobs with the reserved teriyaki marinade during the last few minutes of grilling.
Remove from grill and let rest for a few minutes before serving.
Notes
Serve these Teriyaki Pineapple Chicken Kabobs with steamed rice for a complete meal. Garnish with sesame seeds and chopped green onions if desired.