usagi/serena tsukino was born on earth as a normal human girl. that human girl was born into her powers in her young adult life. it turned out that she wasn't so normal after all. the evil forces of the universe started attacking the earth and the cat luna sought her out as one of the pretty guardians. soon enough, the rest of the guardians were found and together they bound together to save the world.

usagi started having dreams of another life. the more adventures she had, the more the dreams happened of another life. it didn't help when a young girl showed up that reminded her of someone she had met before that things started to click. she was the princess serenity from another time from before the people on the moon had been destroyed.

usagi was not so normal after all, she was girl how had been reborn into another time after serenities demise. she does whatever she can now, no matter how much she might be a crybaby at times, to protect those that she cares about and hold up to what her past self used to do.