Do take note that the yukane and butter has to be at room temperature.*
The dough should be tacky, fluffy, smooth and it should pass the "window-pane" test.
If the dough is too dry, add in water, 1 TBSP at a time. If the dough is too sticky, add in flour, 1 TBSP at a time.
Lightly grease the bowl with some butter.
Transfer the dough back to the greased bowl.
Cover with a damp lint-free kitchen towel and let rise for 30 mins.