Add raw chicken wings to a large ziploc bag.
In a small bowl, whisk together chili pepper paste, brown sugar, soy sauce, water, sesame oil, rice wine vinegar, garlic, ginger, salt, and pepper until combined. Add the marinade to the wings and seal the bag. Let sit in the refrigerator for at least 1 hour.
When ready to cook, preheat grill to 400°F and remove wings from bag, reserving the marinade.
Add wings to the grill and cook until the skin is crispy and they are cooked through, flipping them every 10 to 15 minutes as they cook. This will take about 30 to 40 minutes. They should register 165˚F internally on a meat thermometer.
When wings are cooked, remove them from grill and set them aside on a plate.
Pour marinade into a small saucepan on the stove. Bring the sauce to a boil over high heat and cook for 1 to 2 minutes, stirring constantly.
Brush the finished wings with the sauce. Garnish with sesame seeds and green onion. Serve immediately.