Combine soy sauce, rice wine, garlic, ginger, sugar and sesame oil in a bowl. Trim chicken and cut into strips, each about 3/4" wide and 2-3" long. Place chicken strips in marinade reserving 1/4 to 1/8 cup. Cover with plastic wrap and marinate for 8 - 10 hours in the refrigerator. Remove chicken and discard marinade.

 

Cut skewers to 6" length. Thread the chicken, onions, mushrooms and peppers alternately onto the skewers. Grill about 5 - 6 minutes each side, basting occasionally with reserved marinade. Serve hot.