Combine all ingredients for the marinade in a resealable bag. Add the chicken and marinate for 30 minutes to overnight in the fridge.
When ready to cook, preheat the air fryer to 400 degrees F.
In a wide shallow bowl, stir together potato starch and sea salt.
Transfer the marinated chicken pieces to the potato starch and dredge until evenly coated.
Spray the air fryer basket or tray evenly with cooking spray. Place the coated chicken in a single layer, then spray the top with cooking spray.
Air fry for 14-16 minutes until crisp and crunchy - flipping and spraying again halfway through.
Serve immediately with lemon wedges and Kewpie mayo.