The Princess Mars was one of Princess Serenity's loyal companions. In fact
she is one who displays that "tough love" for her. Mars is very
loyal and stood against Queen Beryl and the Dark Kingdom with the rest of
the senshi. When Queen Serenity decided to send her daughter and the other
senshi to present day Earth, Mars went along as well. Now, the soul of Princess
Mars lies sleeping inside the body of Hino Rei, waiting to be awakened.