Remove silver skin and any excess fat from pork then cut into 1 1/2 inch pieces. Place in a zip top bag.
In a mixing bowl, add soy sauce, pineapple juice, brown sugar, ginger, sesame oil, garlic cloves, and sriracha. Whisk to combine. Reserve 3/4 cup then pour the rest into the bag of pork. Massage to incorporate throughout pork. Let marinate in fridge for 2-8 hours.
Preheat grill to medium-high. Thread pork, pineapple, pepper, and onion onto skewers.
Place kebabs on grill and cook, turning occasionally and basting frequently with reserved marinade. Cook until temperature of pork reaches 150 degrees.
Notes
Cooking time depends on your grill. I used a Traeger smoker/pellet grill and it took 18 min. Internal temp of pork should be 150.