Saya

Saya [さや] is a variety of tōzu, or traditional confectionary. It can be made in either liquid or solid form, as a syrup, taffy, or candy, and can be made from steamed rice, corn, sweet potatoes, or mixed grains. The steamed ingredients are lightly fermented and left to boil in a large pot. It is presumed to have originated sometime in the early Chisō period. 
Saya which is boiled for a shorter time is called goza, and is more like a sticky syrup. It is usually used as a condiment for cooking, flavouring tea or coating other tōzu, or as a dipping sauce for tōgi. The phallic shape of hardened saya had also led the candy to be used as a euphemism for the penis as early as the sixteenth century.