Place the cod in a single layer in a baking dish. In a bowl, whisk together the soy sauce, honey, vinegar, mirin, sesame oil, lime juice, ginger, garlic, red pepper flakes and half of the green onions. Pour over the cod, ensuring that the fillets are evenly coated. Marinate at room temperature for at least 15 minutes or up to 30 minutes. Alternatively, refrigerate for up to 8 hours.