Boil edamame in lightly salted water for about 3 minutes. Remove with a strainer. Add shrimp and allow them to cook for 2 minutes or until shrimps curl and turn pink. Remove and set aside. Discard water.
Fill saucepan again half full with fresh water. Bring it to a boil. Add ume somen and allow it to cook for 2 minutes. Remove with a strainer.
Divide cooked somen between 2 bowls. Top with half of the edamame and 5 shrimp for each bowl.
Pour 2½ cups (600ml) water in the saucepan. Bring it to a boil over medium heat. Add instant dashi, soy sauce, and mirin. When it comes back to a boil, turn off heat.
Pour soup over noodles and topping. Serve immediately.