Start by filling a medium pot with water and bring it to a gentle boil. Add 1 tablespoon of vinegar and carefully lower in the eggs. Boil for exactly 10 minutes.

Transfer the eggs to a bowl filled with ice water for about 5 minutes to halt the cooking process and make peeling easier.

Peel the eggs and separate the egg whites and yolks into two bowls.

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

Finely chop the egg whites and fold them into the yolk mixture.

Take two slices of milk bread and spread the egg salad filling between them. Weigh down with a lightweight plate for about 5 minutes.

Optional: Trim the crusts off the sandwich for a polished finish and slice in half or quarters.