Clean the chicken wings thoroughly and pat dry with paper towels. Place the wings in a sealable plastic bag or shallow bowl.
Add the sake, green onions, ginger, soy sauce, sesame oil, and Chinese five-spice powder.
Marinate in the refrigerator for at least 30 minutes and up to overnight, turning occasionally.
Glaze
Preheat a grill to 375 degrees F (200 degrees C).
Combine the water, honey, soy sauce, mirin, and sake in a small saucepan. Stir over low heat until it thickens slightly, 5 to 10 minutes.
Remove the wings from the marinade and discard the marinade.
Place the chicken wings in a camp oven and cook for 20 minutes, turning every 5 minutes. Transfer the wings to the grill and brush with the glaze. Grill for 5 minutes, glaze, then grill for an additional 5 minutes until the wings are slightly charred. Serve immediately.