Longer names with nicknames tend to be the vogue in the US. As you know my niece is
Miranda nn
Mira (but goes by
nothing else) and I suspect many others are. I wonder what its' stats would be if you combined it with the amount of little girls with the nn
Mira. (I have to say that I'm rather disappointed my SIL had such good taste. :-D)
As for the other names:
Mirai - I love it and will be adding it to my list. It's very much
my style, which means that my boyfriend wouldn't use it. And pretty cool (and apt) meaning.
Miriana - Would get lost in the tons of
Anas out there, I think. It's very pretty...but sooo close to
Mariana,
Brianna,
Liliana,
Tatiana - shall I continue? Too bad, I love it.
Meira - Ditto Mirai. Very much my style, great name, lovely sound. Earthy without being ordinary. Two thumbs up for me. :-D