In a large mixing bowl, combine pork with breadcrumbs, eggs, mirin, green onions, soy sauce, sesame oil, brown sugar, ginger, garlic, salt and pepper. Mix until well combined.
Divide pork mixture into 6 equal pieces and roll into meatballs with your hands.
Place meatballs in a single layer on an air fryer tray and cook at 375˚F for 20 minutes or until the internal temperature reaches 165˚F.
While the meatballs are cooking, combine the soy sauce, chicken broth, brown sugar, sesame oil, and cornstarch in a small mixing bowl. Whisk until cornstarch and sugar dissolve.
Pour the sauce into a shallow saucepan and heat over medium for 4-5 minutes. Continuously stir until desired consistency is reached.
Add meatballs to the saucepan and toss well to evenly coat. To serve, drizzle any extra sauce from the saucepan on top. Garnish with green onions and sesame seeds if desired.