Bishoujo Senshi Sailor Moon

Usagi Tsukino, a typical student who is a crybaby and klutz with low test scores, has mediocre grades. Her humdrum existence is suddenly turned upside-down when she rescues a kitten with a crescent on its head. Later, the cat named Luna reveals their encounter was no accident. Usagi will become Sailor Moon - a planet guardian who has the ability to protect Earth. She is given a brooch which allows her to change into sailor moon. Her new power must be used to protect the city against the evil monsters that steal energy sent by Queen Beryl, the villainous ruler of the Dark Kingdom.
She has other things to think about besides getting used to her new powers. To save the world, she must locate the princess lost in the Moon Kingdom and other Sailor Guardians. She also needs to find the Legendary Silver Crystal.