Konpeito is a form of rock candy or crystallized sugar which is used with the chabako form of the Japanese tea ceremony. In this tamae, the sweets are carried to the tea gathering in a ceramic vessel called a furidashi, which is kept in the tea box. Most furidashi have a small opening, and only the small konpeito will fit into it.
There has been a 2-year shortage of konpeito in the US, particularly of the small size pieces. The US changed their standards for food coloring, and the konpeito, ran into problems. Since the US is such a small part of the world market, it appears that the manufacturers in Japan are not doing anything about it.
I have been able to get my hands on a large quantity of the small konpeito, and should be able to fill all of your needs.