In a medium bowl, whisk together soy sauce, pineapple juice, minced garlic, grated ginger, and brown sugar. Let sit for about 5 minutes.

Cut the chicken breast into 1-inch cubes. Place chicken in a resealable bag and pour the marinade over it, sealing tightly. Refrigerate for at least 30 minutes.

Soak bamboo skewers in water for 30 minutes. Chop bell pepper and red onion into chunks, and prepare pineapple.

Remove chicken from the fridge and thread onto skewers alternating with bell pepper, red onion, and pineapple.

Preheat grill to medium-high heat (around 400°F). Oil grates to prevent sticking.

Cook skewers for 10-12 minutes, turning occasionally, until chicken reaches 165°F and vegetables are tender.

Remove from grill and let rest for a minute before serving.