Rei Hino (火野 レイ Hino Rei), better known as Sailor Mars (セーラーマーズ Sērā Māzu), is a fictional lead character in the Sailor Moon manga series written by Naoko Takeuchi. Rei is a member of the Sailor Soldiers, female supernatural fighters who protect the Solar System from evil.
Rei is the second Sailor Soldier to be discovered by Usagi and the secondary leader of the Sailor Soldiers after Sailor Venus. She possesses powers associated with fire, as well as psychic and spiritual ones.
Aside from the main body of the Sailor Moon series, Rei is featured in two different manga short stories. The first, Casablanca Memories, is entirely about her and her past; the second, Rei and Minako's Girls School Battle, is shared with Minako Aino. A number of image songs mentioning her character have been released as well, including the contents of three different CD singles.
Rei first appears as a miko at the Hikawa Shrine (火川神社 Hikawa Jinja, lit. "Fire River Shrine", renamed Cherry Hill Temple in the DiC English adaptation), and is shown to have an affinity with two crows who live there. It is revealed in the manga that as a child, they "told" her that their names are Phobos and Deimos (the same as Mars' two moons). In the manga, she is portrayed as imperial, ancient, conservative, old-fashioned, traditional, serious, disciplined, and practical, contempting men and disliking modern romantic relationships.