whisk togther the soy sauce, brown sugar, water, garlic, onion, ginger, black pepper, in a larger glass or ceramic bowl. add chicken thigths, and toss to evenly coat. cover the bowl with plastic wrap and marinate the chicken in the refrigerator for at least 1 hour

preheat an outdoor/indoor grill for medium heat and lightly oil grate.

remove the chicken thights on the preheated grill until cooked through, about 15 mintues preside