Add sugar and warm water to a food container. Mix until the sugar is fully dissolved.
Add the rest of the marinade ingredients to the container and mix well.
Gently place the boiled eggs in the marinade and cover with a lid.
Refrigerate at least 4 hours but preferably 8 hours. Rotate the eggs after 2-3 hours (to marinate the other side).
Optional: When ready to serve, sprinkle toasted sesame seeds on to the eggs.