Endimion. Usagi attends Crossroads Junior High School, and is in the eighth grade with Ami and Makoto. She lives in Azabu Juuban with her mother Ikuko, father Kenji, brother Shingo, and feline confidante and guardian, Luna.

Usagi is the reincarnation of the Princess of the Moon who, in the 30th century, becomes Neo-Queen Serenity of Crystal Tokyo. She is the daughter of Queen Serenity, a kind and loving mother who ruled the entire universe from the Moon Kingdom during the Silver Millennium.  Usagi transforms into the Justice Fighter Sailor Moon, the leader of all the Sailor Senshi and one of the most powerful as well. Initially Usagi refused to accept her role as Sailor Moon, but eventually realized that she could not escape destiny and embraced her responsibility to humankind. Although Usagi possesses many qualities unbecoming her status (she is lazy, clumsy, ditzy, gluttonous, and often apathetic), her heart and soul are pure, and she has sacrificed herself many times for others. Usagi may drool over any gorgeous guy she meets, but her heart belongs to Mamoru (knows as Prince Endimion of Earth during the Silver Millennium). Mamoru used to tease Usagi about her hairstyle by calling her "odango atama, but later uses the nickname as a term of endearment. Mamoru affectionately refers to Usagi as "Usako".  In 30th century Crystal Tokyo, Usagi rules the earth as Neo-Queen Serenity with her husband, King