Boil a pot of water and add 1 tablespoon of vinegar. Gently lower in the eggs and cook for 10 minutes.

Transfer eggs to an ice bath for 5 minutes to stop cooking.

Peel eggs under running water. Slice and separate yolks from whites.

In a bowl with yolks, add sugar, black pepper, and Japanese mayo. Mash until creamy.

Chop egg whites into small pieces and fold into the yolk mixture.

Spread the egg salad mixture between two slices of milk bread, pressing down lightly.

Trim crusts for a neat presentation and optionally press down with a small plate.