Soak dried wakame in a bowl of water until rehydrated, then drain.

Slice the green onion into small rounds.

In a pot, bring the seasoning mixture (mirin, mentsuyu, and water) to a boil. Break the dried yuba into halves and add to the pot, cooking for 1 minute.

Add the cooked soba noodles to the pot and briefly heat. Divide the noodles and broth evenly into serving bowls.