Ever make mochi balls?

You do mean Japanese mochi balls, right? I love them to pieces!

Have you tried looking up youtube videos like this one here?

www.youtube.com/watch?v=mo55230BiNY

I think they will be a safer bet than looking up recipes on the internet because you should be able to see a genuine end result with most of the videos.

It seems to me that Jellly is thinking of something besides the mochi balls you are thinking of, amyp. I don't go to frozen yogurt stores, so I don't know what the mochi balls are that Jellly's talking about, but I know what the ones are that you linked to on YouTube.

Jellly, are you sure they're called mochi balls?

Maybe you are looking for little crunchy "Choco" balls? I believe they are also known as Milk Crunchies or Chocolate Crunchies: http://www.beryls.com/index.php?main_page=product_info&cPath=346_328&products_id=7966. These ones seems to be made from some sort of crunchy cereal inside.

They remind me of a small crunchy version of a Malteser or Whopper. Here is some interesting discussion(and speculation) on the making of Maltesers: http://www.guardian.co.uk/notesandqueries/query/0,,-6315,00.html My guess on the creating that type of airy crunchy centre os a Malteser would be a combination of baking soda, sugar, and heat.

The dough in the video is what you want.  It is extruded and cut into the little pieces.  I suppose you could roll it out thin and cut into strings and cut them into little pieces.  It must be kept covered and refrigerated.  You can also flavor it with fruit paste or match green tea powder.

I didn't mean with the filling, just the outer dough that they made.

Jelly, are you talking about daifuku?  Mochiko dough rolled around bean paste?

http://veganyumyum.com/2009/03/daifuku/

This recipe really does work best in the microwave - the stovetop doesn't heat as evenly through the mochiko, and use LOTS of starch (I prefer potato, personally) to stop it from sticking.

You can also get hard pre-made kirimochi at health-food stores, that will puff up when baked or fried - like what's put in shiruko (sweet azuki soup).

Do you mean "popping boba"  http://www.poppingboba.com/ or http://alturl.com/e4mf3

Here are the popping boba ingredients...http://www.poppingbobas.com/popping-boba-ingredients/. I am wondering if the "seaweed extract" actually refers to agar.

Or how about tapioca pearls?

Tapioca pearls can be purchased whole, they come in small to large sizes, and just need to be gently simmered.