Origami balls are called “Kusu-Dama”.

They were introduced into Japan in the Heian period from China (The Heian era is from794 a.d. to 1192 a.d. )
Originally they were made of herb medicines put into brocade and decorated with artificial flowers into an ornamental scented ball. They were hung on a reed screen or a pillar to give a wide berth to the evil spirit or as a charm and bringer of good luck.

More recently, the Kusu-Dama is made from Origami paper, and the shape of all polyhedrons. So, it is called "unit origami".

Many Japanese people enjoy making and decorating the Kusu-Dama. They are still developing today.