The Usada family ~How saitom named them?~

More and more saitom characters are coming into being, and the Usada family has been gathering attention through the new merchandises. I guess most of you are not interested in the family name itself but have you ever wondered how saitom named it or why the name?
This post is nothing but my speculation that is not based on the info available for now. So please do not take it too seriously.

In Japanese, usagi is rabbit. As you can see their outfits, the Usa as in Usada definitely comes from usagi. For the first two Chinese characters(宇佐), perhaps saitom chose random characters with two syllables and the same sound as Usa. Da(田)means field(s), which is among the most common used for Japanese surnames such as Tamura(田村), Tanaka(田中), Morita(森田), and you name it. Usa + this one (da) makes three syllables that sound more natural than just two, and also for easy pronunciation.
So how about their first names? 
I’m not quite sure what saitom named the sisters after. The only thing I know is that all of the first names in the Usada family consist of two hiragana1)Hiragana has one syllable for each. characters only2)ゆう(Yuu)、みみ(Mimi)、まみ(Mami).
Generally speaking, people consider hiragana cute, gentle, simple, and sometimes uneducated because it is the simplest character of the Japanese language that infants learn to write first3)Of course, adults do use it, too.. And therefore I’d say saitom aimed to make them sound pretty, easy to remember, and pleasing to the ears4)Some might think two or three syllables are easier to pronounce than four.; that’s pretty much it.
Then, what can their names mean?
Yuu(ゆう) would most likely be written in Chinese characters as . means “gentle,” “superior,” or “excellent,” often used for female. Meanwhile, Mimi(みみ) would not be spelled likewise because it could look unnatural. It follows that hiragana is the most suitable for the name. Mimi has the same sound as 耳(ear). I have a vague idea, but saitom might have got inspired by her long bunny ears? Who knows?
For Mami, I don’t know anything about her yet, so let’s put her aside for now.

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