Left
Narwhals do construction with their left hands (or flippers, I guess). That's because all narwhals are left-handed!
Picture a bunch of narwhals constructing an underwater ice village. They're all working away with their left hands.
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ひだり
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In their left hands, the narwhals all hold saws (さ). That's because the ice for their homes is already there, so they just need to saw away at them to make the shapes they want. Narwhal construction is actually very simple.
If you're right-handed, imagine trying to use these left-handed saws. It flips and flops all over until you drop it. But if you're left-handed it feels just right!