Preheat your air fryer to 375°F.
Pat chicken dry with paper towels. Season with salt, pepper, garlic powder, and onion powder.
Set up a breading station: one plate with flour, one with beaten eggs, and one with panko.
Dredge chicken in flour, dip into egg, then press into panko until fully coated.
Spray both sides of the chicken with cooking spray and place in the air fryer basket.
Cook for 10 to 12 minutes, flipping halfway, until golden brown and crispy.
Meanwhile, whisk together ketchup, Worcestershire sauce, soy sauce, and sugar to make the tonkatsu sauce.
Slice the cooked chicken into strips and serve with sauce on the side.