In a medium bowl, combine gochujang, soy sauce, rice wine vinegar, brown sugar, sesame oil, ginger and garlic. Reserve 2 tablespoons and set aside.
In a gallon size Ziploc bag or large bowl, combine gochujang mixture and chicken; marinate for at least 2 hours to overnight, up to 8 hours, turning the bag occasionally. Drain the chicken from the marinade, discarding the marinade.
Preheat grill to medium high heat. Thread chicken onto skewers; brush with canola oil.
Add skewers to grill, and cook, turning occasionally, until the chicken is completely cooked through, reaching an internal temperature of 165 degrees F, about 10 minutes. Brush skewers with reserved gochujang mixture, cooking for an additional 1-2 minutes.
Serve immediately, garnished with green onion and sesame seeds.