Bring a pot of water to a boil. While you are waiting for the water to boil, whisk together the sesame oil, rice vinegar, and tamari in a medium bowl and set aside.
Boil the edamame for 3 minutes, then add the corn and boil for another 2 minutes. Drain into a colander and run under cold water. When it is cool enough to touch, add the edamame and corn to the dressing and toss to combine. Add the toasted sesame seeds and toss again. (To toast sesame seeds, place in a small pan over medium heat. Gently toss in the pan until they turn golden brown. Watch carefully as they can go from white to burnt quickly!)