Piro is a stray cat the group takes in, even though Nayuki's allergies make it less than ideal. Makoto bonds with the cat pretty quickly—so much so that Piro basically lives on her head most of the time. The name came from Yuuichi, who jokingly suggested "Piroshki" (the Russian word for meat buns). Makoto shortened it to just Piro, though she had no clue what the original name actually meant.
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