In a bowl, combine soy sauce, sake, ginger, garlic, and sesame oil. Add chicken pieces and marinate for at least 30 minutes, or up to 2 hours in the refrigerator.
Preheat the air fryer to 400°F.
Remove chicken from marinade and coat each piece in cornstarch.
Place the chicken in the air fryer basket in a single layer, cooking in batches if necessary.
Air fry for 12-15 minutes, shaking the basket halfway through, until golden brown and cooked through.
While the chicken is cooking, prepare the miso glaze by whisking together miso paste, honey, and rice vinegar in a small bowl until smooth.
Once the chicken is done, drizzle the miso glaze over the crispy chicken and toss to coat.
To assemble the rice bowl, divide cooked rice among bowls, top with glazed chicken, shredded carrots, cucumber slices, and green onions.
Sprinkle with sesame seeds before serving.