Preheat oven to 400°F (200°C). Line a baking dish with parchment paper.
Whisk together miso paste, soy sauce, mirin, honey, olive oil, garlic, and ginger in a small bowl.
Pat the sea bass fillets dry with paper towels. Place them in the baking dish.
Brush the miso mixture evenly over the fish, coating it well.
Bake uncovered for 12–15 minutes, or until the fish flakes easily with a fork.
Remove from oven and rest for a couple of minutes before serving.
Garnish with green onions, sesame seeds, and serve with lemon wedges.