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 Minako Aino.