Food

What can be opened but cannot be closed?

related riddles

This is a Japanese food consisting of cooked vinegared rice sushimeshi combined with other ingredients, usually raw fish or other seafood

I come out of the earth, I am sold in the market. He who buys me cuts my tail, takes off my suit of silk, and weeps beside me when I am dead.

What nut has a hole and is squishy?