In a small bowl, whisk together the eggs, mirin, sugar, and soy. Add the egg mix, along with the butter to a cold pan.Using a rubber spatula, stir occasionally so the eggs cook slowly and evenly, pushing only every so often so you end up with large curds, about 2-3 minutes. Undercooked is better as they’ll continue to solidify off the heat.Slide onto a bowl of white rice, season with salt and pepper, and top with nori. Enjoy!