In a medium saucepan, bring 1 1/2 cups lightly salted water to a boil. Add rice, reduce to a simmer; cover and cook, 30 minutes.
Stir in edamame; cover and cook until rice is tender, 15 to 20 minutes. In a small bowl, stir together lime juice, vinegar, oil, and sugar until sugar is dissolved.
With a fork, stir lime juice mixture and scallions into rice; season with salt and pepper.