In a medium-sized bowl, add the mirin, white miso paste, honey, soy sauce, rice vinegar, minced garlic, and the white part of the minced green onions. Mix well to create a glaze.
Add the boneless skinless chicken thighs into the bowl with your marinade and massage the sauce into each piece of chicken thoroughly.
Line your air fryer tray or basket with parchment paper or aluminum foil.
Place each piece of marinated chicken in a single layer in your air fryer basket and pour all remaining miso glaze over the chicken.
Set your air fryer to cook at 375 degrees Fahrenheit for about 20 minutes, flipping halfway through. Broil for an additional 2 minutes for a crust.
Using a meat thermometer, ensure that the internal temperature of your chicken reaches at least 165 degrees Fahrenheit.
Baste your cooked chicken with any leftover pan juices before serving. Garnish with fresh green onions and cilantro.