Minako seems to usually be written with some combination of characters for "beauty" and "child"

but I have totally cheated and Minako uses an alternate version written with characters for "everything" + "child".

Because the Universe Arcana.

Also various Google search results suggest that the characters used to write Arisato mean something along the lines of "exist" and "birthplace" but I have no idea how accurate that is.

Squall: A brief, sudden and violent windstorm, often with rain or snow, because Square Enix loves their weather names.

And of course Leonhart = Lionheart, which I don't think needs further explanation.

I do not know if Matsuka actually means anything, but the first part sounds like the Japanese word for "pine." A symbol of longevity! Ha ha ha.

Jonah means "dove."

Hm, I can't think of any others of interest.

(If any of this is interesting in the first place. Mostly I get away super easy for this meme.)