What is the plural of “Mewis”? It’s the kind of question that plagues people in the same way that makes people ask why is the plural of goose “geese” but the plural of moose is not “meese.” The actual answer is that the root language of the word determines the plural, something something linguistics, but in the case of the Mewis...Mewises...Mewii...sisters, there’s still no definitive answer. They gave it a shot, though.
In the meantime, “Mewii” as a word is extremely fun and evokes the Dioscuri, more commonly known as the twins Castor and Pollux.