Wash the kabocha pumpkin thoroughly, remove the seeds, and cut it into small pieces.
Steam the kabocha pumpkin for 15 minutes.
Mash the steamed kabocha and let it cool, then mix in sugar and salt.
Add flour, yeast, and milk, and knead into a dough.
Let the dough rise for 1 hour.
Divide the dough into suitable portions and shape into balls.
Bake in a preheated oven at 180°C (356°F) for 20 minutes.