In a mixing bowl, combine soy sauce, honey, rice vinegar, olive oil, minced garlic, grated ginger, and black pepper. Whisk until well blended.

Add the cubed chicken thighs to the marinade, ensuring they are fully coated. Cover the bowl with plastic wrap and refrigerate for at least 30 minutes, or up to 2 hours for more flavor.

In a small saucepan over medium heat, combine diced pineapple, brown sugar, and soy sauce. Stir occasionally until the mixture begins to simmer.

In a separate bowl, dissolve cornstarch in water. Once the pineapple mixture is simmering, add the cornstarch mixture and stir continuously until the glaze thickens, about 2-3 minutes. Remove from heat and set aside.

Preheat the grill to medium-high heat.

Thread the marinated chicken, red and green bell pepper pieces, and red onion wedges onto the soaked skewers, alternating between chicken and vegetables.

Place the skewers on the preheated grill and cook for about 10-15 minutes, turning occasionally, until the chicken is cooked through and has nice grill marks. The internal temperature should reach 165°F (75°C).

During the last few minutes of grilling, brush the skewers with the pineapple glaze for added flavor.

Remove the skewers from the grill and let them rest for a couple of minutes. Serve hot with extra pineapple glaze on the side for dipping.