Serena 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 kinda nd loving mother who ruled the entire universe from the Moon Kingdom during the Silver Millennium. Serena transforms into the Justice Fighter Sailor Moon, the leader of all the Sailor Scouts, and one of the most powerful as well. Initially Serena refused to accept her role as Sailor Moon, but eventually realized that she could not escape destiny and embraced her responsibility to humankind. Although Serena 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. Serena may drool over any gorgeous guy she meets, but her heart belongs to Darien (known as Prince Darien of Earth during the Silver Millennium). Darien used to tease Serena about her hairstyle by calling her "meatball head" ("odango atama" or "dumpling head" in Japanese), but later uses the nickname as a term of endearment. In the Japanese version, Darien (Mamoru) affectionately refers to Serena (Usagi) as "Usako". In 30th century Crystal Tokyo, Serena rules the Earth as Neo-Queen Serenity with her husband, King Darien.

Serena attends Crossroads Junior High School, and is in the eigth grade with Amy and Lita. She lives in Azabu Juuban with her mother Ikuko, father Kenji, brother Sammy, and feline confidante and guardian, Luna.