Once the Professor came across this in a nursery school & was so impressed that he himself wanted to devise a refined method & technique of making it. Though after 200 experiments & using his expertise, the Professor was finally able to devise a method of making it, which was easily followed by the children too.
Once this new technique was taught & the children knew it, spent long hours to knead the mud & then polish it till they got their own mud ball that shines.
How to Make Shiny Ball "Dorodango"
Here is how to make the shiny ball:
"1. Pack some mud into your hand, and squeeze out the water while forming a sphere.
2. Add some dry dirt to the outside and continue to gently shape the mud into a sphere.
3. When the mass dries, pack it solid with your hands, and rub the surface until a smooth film begins to appear.
3. Rub your hands against the ground, patting and rubbing the fine, powdery dirt onto the sphere. Continue this for two hours.
4. Seal the ball in a plastic bag for three or four hours. Upon removing the sphere, repeat step 4, and then once again seal the sphere in a plastic bag.
5 Remove the ball from the bag, and if it is no longer wet, polish it with a cloth until it shines."
It's simply amazing to know that you can really make a ball out of mud & make it shine too.
At Kyoto University of Education you have in-depth information along with pictures & videos.
Video 1| Video 2| Video 3| Video 4| Video 5