Add your eggs to a small or medium sauce pan, then fill it with water until it covers the top of the eggs.
Boil the eggs for about 10 minutes.
Then immediately transfer the eggs to an ice bath (ice cubes in a bowl of water) to quickly cool the eggs down and prevent them from further cooking.
Once your eggs have cooled down, remove the shells from the egg.
Now using a knife, separate the egg whites from the egg yolks.
Dice the egg whites finely into tiny pieces and then combine it with your egg yolks, making sure to mash up the egg yolks using a fork or spoon.
Next, add in the dijon mustard, mayonnaise, sugar, salt, black pepper and mix everything well together.
Now add the egg mixture on top of your shokupan bread and serve.
Optional: You can apply some unsalted butter to the Shokupan bread prior to adding in the egg salad if you prefer