In a small bowl, combine soy sauce, honey, mirin, rice vinegar, sesame oil, minced garlic, and grated ginger to make the teriyaki sauce.
In a separate small bowl, mix cornstarch and water until smooth, then add to the teriyaki sauce mixture and stir well.
Pour the sauce mixture into a small saucepan and cook over medium heat, stirring constantly, until the sauce thickens, about 3-4 minutes. Remove from heat and let cool slightly.
Pat the salmon fillets dry with paper towels.
Brush half of the teriyaki sauce evenly over the salmon fillets.
Preheat the air fryer to 400°F (200°C) for 3 minutes.
Place the salmon fillets skin-side down in the air fryer basket, making sure they do not overlap.
Air fry the salmon at 400°F (200°C) for 10 minutes.
After 10 minutes, brush the remaining teriyaki sauce over the salmon fillets and air fry for an additional 2 minutes.
Carefully remove the salmon from the air fryer and transfer to serving plates.
Garnish with sesame seeds and sliced green onions before serving.