01 - Bring a pot of water to a full rolling boil.
02 - Gently lower the eggs into the boiling water using a spoon. Boil for exactly 7 minutes for a slightly runny yolk.
03 - Prepare an ice bath while eggs cook. Immediately transfer eggs to the ice bath once cooking time is complete. Cool for 5 minutes.
04 - Carefully peel the cooled eggs, removing all shell fragments.
05 - Combine soy sauce, water, mirin, and sugar in a zip-top bag or small container. Stir or shake until sugar completely dissolves.
06 - Place peeled eggs in the marinade, ensuring they are fully submerged. Refrigerate for at least 4 hours, preferably overnight, turning occasionally for even color.
07 - Remove eggs from marinade, slice in half, and serve atop ramen or as desired.