Bring a pot of water to a boil, then reduce heat to a gentle boil. Swirl in vinegar.
Submerge the eggs and boil them for 5-7 minutes (5 minutes for runny yolks, 7 minutes for soft but firm yolks). Swirl the eggs gently in the boiling water for the first 2 minutes of cooking to help center the yolks.
Remove the eggs and submerge them in ice water to cool.
Carefully peel them and set into a bowl or baggie for marinating.
Whisk together the marinade ingredients and pour into a saucepan. Bring to a boil. Reduce heat and simmer for 1 minute. Cool completely.
Pour the marinade over the eggs. Seal or cover then marinate the eggs in the refrigerator for at least 4 hours. Marinate longer for a stronger flavor.
Slice in half and serve over bowls of ramen.
