Sailor Moon・Cards・Sailor Mars

Along with being a student, Rei also lives and works as a shrine maiden ("miko" in Japanese) at Hikawa Shrine (Cherry Hill Temple in the DiC dub), where her grandfather is head priest. The shrine is based on real-life Hikawa Shrines, particularly the one located in Azabu Juban, where Sailor Moon's story is set. Takeuchi tweaked the original name of the shrine by changing the kanji for ""ice"found in the word Hikawa with the kanji for ""fire,"as a reflection of Rei's fire-related powers. Rei's values in life are strongly influenced by spirituality and her lifelong dream is to become the head priestess at her grandfather's shrine. Meditation is given as her strong point, while she enjoys fortune-telling as a hobby. Her old-fashioned values are further underscored by the contrast between her favorite subject, classical Japanese literature, and her least favorite, modern society.

In the manga, Rei is portrayed as disciplined, traditional, and contemptuous of romantic relationships. She retains her serious personality in the anime adaptation, but is also greatly interested in pop culture. She excels at music by singing, playing the piano and guitar, and composing songs for a school festival. Rei and Usagi Tsukino (Sailor Moon) argue frequently, which makes for a very tempestuous relationship. However, these arguments are usually superficial and over the course of the series, Rei becomes more loyal to and respectful of Usagi. Due to the lack of respectable males in her life, Rei harbors a generally low opinion of men. She is uninterested in romance because she considers them emotionally weak and untrustworthy.

Rei is one of few Sailor Moon characters who is able to use special powers in her civilian form. These are mainly the result of her role as a shrine maiden, which gives her heightened spirituality. Most of Sailor Mars's attacks are offensive but with her psychic talent, Rei is able to do fire readings and dispel evil spirits. She also occasionally experiences unprompted premonitions. In the manga, she is listed as the secondary leader of the Sailor Soldiers, after Sailor Venus. This fact is especially significant in the live-action series. Although she sometimes adopts an aloof, big-sisterly attitude around them, Rei does love and cherish her fellow Sailor Soldiers dearly.