so! in eastern folklore, there is a myth about the rabbit on the moon. i grew up with picture books abt it (i’m chn). for japan specifically, they call this 月の兎, “tsuki no usagi,” and it stems from the shadows/markings looking like a rabbit making mochi.
commonly, it’s depicted as a white rabbit. hori makes the connection overt with his coloring of miruko and direct visual association with white rabbits
in addition to this, all of miruko’s attacks not only involve the word “moon” (luna), but also have a circular or arcing motion involved, reminiscent of the moon’s shape

a key part i noticed about the japanese-specific myth, though, is that the rabbit sacrifices itself for a cause.