In a saucepan, over high heat, bring the water and garlic to a boil.
Stir in the frozen edamame, and cook until the edamame is hot, and the liquid has nearly evaporated, about 5 minutes.
Reduce the heat to medium-high and stir in the teriyaki sauce, brown sugar, vinegar, and sesame oil.
Stir constantly until the sauce has thickened and coats the edamame, about 4 minutes.
Sprinkle with sesame seeds to serve.