In a mixing bowl, whisk together the soy sauce, brown sugar, rice vinegar, cornstarch, minced garlic, fresh ginger, and black pepper until completely combined.
Pour the sauce mixture over the wings in the slow cooker, ensuring they're evenly coated.
Cover and cook fresh or thawed wings on LOW for 4-5 hours (or HIGH for 3-4 hours) until the chicken is tender and fully cooked to an internal temperature of 165°F.
Once cooked, preheat your oven broiler and line a baking sheet with aluminum foil. Spray with cooking spray to prevent sticking.
Transfer the cooked wings to the prepared baking sheet and baste generously with the teriyaki sauce from the slow cooker.
Broil for 3-4 minutes, then flip the wings, baste again, and broil for another 3-4 minutes until they achieve that perfect sticky, slightly crispy exterior.
Garnish with sliced green onions and a sprinkle of sesame seeds before serving.
Notes
For the crispiest wings, pat them dry before placing in the slow cooker.
Don't skip the broiling step! This is what transforms them from good to amazing by caramelizing the sauce.
If you prefer an even thicker glaze, transfer about 1½ cups of the sauce from the slow cooker to a small saucepan. Bring to a boil and whisk constantly for 1-2 minutes until it reaches your desired consistency.
Keep a close eye on the wings while broiling as the sugar in the sauce can burn quickly.
For maximum flavor, toss the wings in the thickened sauce after broiling for one last coating.