Boil ramen noodles 3 minutes or just until tender, drain well. Do not overcook.
While the noodles cook, whisk soy sauce, sesame oil, brown sugar, red pepper flakes, water, and rice vinegar in a small bowl. Set aside.
In a 10-inch skillet, heat the oil over medium-high heat. Add ginger, garlic, and whites of green onions. Cook just until fragrant, 1-2 minutes.
Add remaining sauce ingredients and ½ of the remaining green onions. Simmer for 1 minute.
Stir in ramen, cook 1-2 minutes or until heated through. Top with remaining green onions and sesame seeds.
