In a medium bowl, whisk together soy sauce, pineapple juice, brown sugar, ketchup, garlic, ginger, sesame oil and Sriracha. Reserve 1/4 cup and set aside.
In a gallon size Ziploc bag or large bowl, combine soy sauce mixture and chicken; marinate for at least 1 hour to overnight, turning the bag occasionally.
Drain the chicken from the marinade. Preheat grill to medium high heat.
Add chicken to grill and cook, flipping once and basting chicken with reserved 1/4 cup marinade until cooked through, about 5-6 minutes on each side.
Serve immediately, garnished with cilantro, if desired.
