Element
If you look really close at your rib cage, you'll see what looks like millions of tiny little threads. But those aren't threads — they're the essential elements of life as we know it.
そ, す
もと
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The essential elements of life need to be kept clean just like everything else, so you make sure to wash them with soap (そ) every single day. This turns out to be pretty hard since the elements are shaped like tiny microscopic threads, but you do your best.