Place peeled satsuma mandarin in boiling water.
Add baking soda and let boil over low heat for about a minute. Remove and place the satsuma mandarin in chilled water. Remove all of the pith on the satsuma mandarin.
In a bowl, place all of the ingredients for mochi dough and mix well until smooth. Microwave at 600W for 1 minute and 20 seconds.
Remove from the microwave and mix the mochi dough using a spoon. Take a scoop and stretch it out until it’s thin.
Place the mochi dough on saran wrap, spread white bean paste evenly and place satsuma mandarin on top. Wrap the dough around the fillings completely and form into a round shape. Cut in half to serve!