What is a Japanese dessert or confection that is shaped like Hostess Snowballs but is sort of squishy and jellyish sweet and covered with some sort of powder and where can I buy them?

I had this at a Japanese restaurant once. It was called MOCHI. I have no idea what is in it. It was light green- coloured and flavoured with green tea. It was just beautiful, delicious, heavenly, with a really wonderful texture. I hope someone will answer this further and explain how it is made. It's the best dessert in the world.