Peel Japanese sweet potatoes and cut into chunks. Boil or steam until soft. Drain and mash while still hot. Insert skewer or folk into the center of the sweet potato and pull it out. when it is fully baked, there is no any wet batter on it.

Add butter, sugar and milk to the mashed potatoes and mix well.

Form the mashed potatoes into trees.

Bake in the oven or toaster oven until the topis brown.

Remove the beans skins (if you don't care about beans skin you don't need) then mash them.

Add heavy cream and sugar to the mashed beans and mix well, add the heavy cream little by little until it smooth.

Add matcha powder (or green food coloring).

Add a little water little by little to shiratama powder (sweet rice powder) and kned it until the powder get as tender as an earlobe.

Add a little yellow food coloring and mix well.

Form the mixed shiratama powder into stars.

Boil them for 5 min then put them into icy water (or cold water).

Pad dry on paper towel then joint the star and the tree to use a tooth pick.

It's done !!