Mulberry
You take a stool, another stool, and yet another stool and stack them on top of a tree to make a mulberry bush. This is how mulberry bushes are made. You take three stools and you put them atop a tree.
Imagine putting three stools on top of a tree and watching it transform into a mulberry. The science of nature!
そう
くわ
None
Your mulberry tree then produces a quantity (くわ) of mulberries. Yum.
Imagine the huge quantity of mulberries growing from your stool tree. Imagine picking them all. What an enormous quantity of mulberries you now have.