There is almost a 3500-year history with Tonbodama, which started in Mesopotamia. In Japan, there are fewer than 100,000 Tonbodama left at the 1200-year-old Shosoin (storage house for Emperor family). Also, there was a very accurate description left behind about how to make Tonbodama.
Why do people call them Tonbodama? Some suggested because it looks like a Dragon- Fly’s eyes. (Tonbo = Dragon Fly)