While the eggs are in the ice bath, mix the marinade in a jar or sealable container.
Pour soy sauce, mirin, and water into the jar or container.
Add spicy red pepper.
After eggs have been in the ice bath for 3-4 minutes, carefully remove and peel them.
Add eggs to the marinade.
Cover the eggs and marinade with a paper towel. Ensure that the paper towel absorbs the liquid. This weight will make sure the eggs are fully submerged.
Seal the jar or container with a lid.
Place in the refrigerator for 2- 8 hours. I recommend overnight.