Steam or blanch the edamame beans until tender, then rinse them under cold water. Drain and put them in a bowl.
Cut the cucumber in half lengthwise, then scoop out the soft flesh. Slice the cucumber into half-moon shapes, then cut them in half again. Add these to the beans.
Peel the avocado and cut the flesh into small cubes. Add these to the beans.
Cut the radishes into thin wedges, then add these to the beans.
Add the soy sauce, rice wine vinegar, sesame oil and garlic to the salad. Toss gently. Taste and adjust it to your liking - you can add some lime or lemon juice too.
Cut the nori sheet into thin strips and scatter these on top of the salad together with the sesame seeds, if used.
Rest for 5 minutes before serving.