The central character of the series is Tsukino Usagi, a rather flaky, good-hearted schoolgirl. She tends to be rather clumsy and whiny, but gets more bearable as the story continues. (Thank goodness.) She has golden hair, done up in ponytails streaming from two buns atop her head - hence her nickname, odango atama. (literally, "dumpling head.") She doesn't really like the nickname, even though she's the one to insist that the buns are called "odango"...
Usagi's one saving grace is her confidence in the fact that things can be made right. No matter how bad things are, she's sure that they'll work out; no matter how evil people are, she's sure that they're good inside. She's also bubbly and enthusiastic, but tends to act like a child. She doesn't do all that well in school, either, which is not a good thing in Japan.
However, her guardian cat Luna reveals to her that she has an alternate persona - the superhero Sailormoon. Even though she cries and wants to run away during her first fight, the added responsibility slowly begins to mature her, and her natural enthusiasm is redirected towards becoming the best figher possible. As the fighter Sailormoon, (as well as Super Sailormoon, Eternal Sailormoon, etc, etc depending on where in the series you are) she fights wholeheartedly to keep Earth and Moon free from enemies who want to drain the energy and steal the dreams of Earth. With the help of her friends, the Sailor senshi, she goes through a lot of personal growth, finally becoming a truly magnificent fighting force for freedom and justice.
Anyone who can read Japanese can see the pun in Usagi-chan's name; Usagi is the word for "rabbit," and "Tsukino" literally translates to "of the moon." Hence, Sailor Moon, the Rabbit of the Moon. There is, I'm told, a Japanese myth about a rabbit on the moon... But there's more.
It turns out that Usagi is actually the reborn Princess Serenity of the Moon. Back in the time of the Silver Millenium, the Moon Kingdom was attacked and all but destroyed; the Queen Serenity sent her daughter forward in time to reclaim her birthright. Along with the Princess, the Queen also sent forward in time the Sailor Senshi, also known as the Planet Princesses, the protectors of the Moon Princess. She also sent her daughter's lover the Earth Prince Endymion.
Ah yes, the Earth Prince. I can't really talk about Usagi unless I mention Mamoru, can I? They come as a set, and are incomplete without each other. Chiba Mamoru is, basically, the love of Usagi's life, as she is his. Their love for each other, of the Moon Princess Serenity for the Earth Prince Endymion, was why they both died back in the Silver Millenium -- Endymion died protecting Serenity, and she died of grief for his loss. In the present, their reincarnations discover each other again, and have a second chance to make things right. The series deals with the lasting bond between them -- an enduring love in a dangerous life, where it is entirely possible that they could lose each other at any moment.
They're highly possessive of each other - Usagi goes into fits when she sees how protective Mamoru is of Chibiusa, and gets dark suspicions about Michiru hanging aroud him all the time... but it's mutual; Mamoru gets really jealous when he sees Haruka bend to kiss Usagi. (God knows what he'd have done if he'd seen Seiya kiss her. Though come to think of it, Usagi was mostly vulnerable because Mamoru was dead... so the point is moot.) At one point, they were so mad at each other that it took Chibiusa at her bubbliest to get them back together again... <grin>
In the 30th century, the story goes, they will create a place of shimmering beauty called Crystal Tokyo - a modern-day Silver Millenium, where that which went wrong years ago is made right, where true love wins out over all, and everyone will live happily ever after. Not too bad a fairy tale, in the larger scheme of things.
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