Rinse the chicken in water and pat dry with paper towels. Season the chicken lightly with kosher salt and set aside.
Add the soy sauce, sugar and mirin to a small sauce pan. Mix the cornstarch in the water and add to the sauce pan. Bring the mixture to a boil, then reduce to simmer. Add the rice vinegar and Japanese 7 spice and cook for 5-10 minutes or until the sauce thickens, stirring occasionally.
Spray a grill pan with cooking spray and bring to medium high heat. Add the chicken thighs but don't crowd the pan. Cook the chicken for 5-7 minutes on each side. Baste each side of the chicken with the 7 spice teriyaki sauce and cook for an additional 2 minutes each side. Remove from the pan, lightly tent with foil and rest for 3-5 minutes. Repeat with the other chicken thighs if needed.
To prepare the bowls, spoon rice into the bottom of the bowl then layer with shredded carrot, shredded green onion and edamame. Slice or chop the chicken thighs and place on top then drizzle with the 7 spice teriyaki sauce. Garnish with sesame seeds.
For the Japanese 7 Spice (Shichimi Togarashi)
Process nori in a mini food processor or blender until fine flakes form. Add remaining spices and blend. Store tightly in a covered jar in a cool, dry place.