Princess Rei is the crown princess of the planet Mars. Mars is a part of the Silver Millinium Alliance. Therefore, one of the duties as the Princess of Mars, is to be a Guardian to Princess Serenity of the Moon, crown princess of the Silver Millinium. Princess Mars holds within her, the power of Mars, and she uses this power, in her senshi form to protect Princess Serenity. In the Silver Millinium, Princess Rei, lived on the Moon, with Serenity and the other 4 inner guardians of the Princess. It is rumored that Rei met and fell in love with one of Prince Endymion's guardians, General Jedite. Unfortunatly, Jedite became one of the many minions of the evil Queen Beryl. In the final battle, which became the downfall of the Moon Kingdom and the Silver Millinium, the Princess of Mars, died attempting to protect Princess Serenity, and her Kingdom. Princess Rei was sent to the future by Queen Serenity along with Princess Serenity, and the other Guardians.
Rei
Raye Hino or Hino Rei (jap) is the Priestess of the Cherry Hill Temple, in Toyko, Japan. Her Grandfather owns the Temple, and Raye lives there with him. Raye's Mother died in childbirth, and her Father travels the world and doesn't really visit much. Raye attends a private school in Toyko. Raye is very intelligent, gets good grades, and excells at most any task that she sets out to do. Raye has some psychic abilities that at times, make her somewhat of an outcast, and also lonely, unitl she meets Bunny. Raye's best friend is Bunny, even though they sometimes will give you the impression that they don't get along. Bunny and Raye's personalities are very different, and so they complement each other. They treat each other like sisters and have a very strong bond, despite their constant name calling and bickering. At times, you may get the impression that Raye is mean to Bunny, but she really just cares about her and is trying to keep Bunny's carefree ways in check. In the first season, Raye tries to give it a go with Darien (before Darien and Bunny realized who they are), but Darien was more interested in Bunny anyways. Later on, his one struggling musican, named Chad comes to the temple for help and ends up moving in. After awhile, Raye and Chad fall in love.
Sailor Mars
Sailor Mars is the Guardian of FIRE. Mars is the second in command of the Sailor Soldiers, and the Inner Senshi. She posesses special psycic abilities that also make her a very powerful scout. Sailor Mars is one of the four Inner Senshi of Princess Serenity. It is her duty to protect the Princess of the Moon at all costs. Sailor Mars posseses the powers of the Senshi of Mars, every planet bestowing it's powers to one senshi, she controls the firey red planet. As the guardian of fire, Sailor Mars has a firey personality as well, causing her to at times lash out at Sailor Moon. Even so, Sailor Mars is undoubtably one of the most trustworthy Guardians of the Princess. You can always count on her to have Sailor Moon's back, being that they are best friends. (When they aren't fighting).
Super Sailor Mars
Super Sailor Mars is a more powerful form of Sailor Mars. Her attacks become more powerful, as do her psychic abilities. Sailor Mars becomes Super Sailor Mars in the SuperS season. Her fuku doesn't change that much, except that her sleeves turn into see-through fabric, the bow in her back gets longer, her necklace gets a star on it, and her broach turns from a circle to a heart.
Eternal Sailor Mars
Eternal Sailor Mars is the final form of Sailor Mars. In her Eternal form, her powers are at their greatest. Her fuku changes in that she gets a layer of white under the red. Her red heels change to white boots, and her heart broach as Super Sailor Mars turns into a star. In the cartoons, you never see any of the Eternal forms of the senshi. In the manga we only see a few images drawn by Naoko.
Queen Rei of Mars, and Guardian of Neo Queen Serenity
Queen Rei of Mars, is the future Rei. She rules from Crystal Tokyo, in the 30th century. Queen Raye is also a guardian and best friend of Neo Queen Serenity, ruler of the Crystal Millinium. We don't know much about Queen Raye since we only see glimses of her when the scouts go into the future due to Rini, but she remains a loyal scout and I'm sure she is great ruler of the planet Mars.
