Make the Yudane dough. In a small bowl with the flour, pour the boiling water. Mix until incorporated and sticky. Cover and refrigerate for at least 4 hours or overnight for up to 3 days.
Proof the yeast. Heat the milk in a saucepan or microwave at lukewarm temperature or between 112 °F to 115 °F. Add and mix in the active dry yeast and sugar to feed the yeast.
Make the white bread dough. In a bowl of a stand mixer with the dough hook attachment, mix the flour, salt and sugar. Add in the Yudane dough and proofed yeast.
Kneading the dough. Knead by hand for 12 minutes or by stand mixer for 8 to 10 minutes. Mix on speed 2 for 5 minutes, then add the butter. Knead for about 3 to 5 more minutes or until smooth and elastic.
Test the dough. Do a windowpane test by stretching the dough without tearing easily to make sure the dough is kneaded enough.
Proofing the dough. Grease the bowl and the dough with butter or oil. Cover and proof the dough in a warm place for about 1 to 2 hours or until it doubles in size.
Shaping the dough. Deflate the dough and place the dough on a floured board and flatten to remove more air bubbles. Shape into a ball and let it rest for 20 minutes. Use a rolling pin to flatten the dough and roll it into a cylindrical shape with the length size of the loaf pan. Pinch the flattened dough end sealed down and transfer in the loaf pan.
Final dough proofing. Cover the dough with a kitchen towel and let it rise in a warm place until it reaches the loaf pan rim.
Baking the white bread. Bake in a preheated oven at 335°F for 25 to 30 minutes. Cover loosely the top of the bread with aluminum foil after 10 to 15 minutes of baking to avoid a darker crust.
Cooling the bread. Remove the bread immediately from the loaf pan to avoid the bread steaming and shrinking inside the loaf pan. Let it cool in a cooling rack to cool completely before slicing.