The Sailor Moon manga series features an extensive cast of characters created by Naoko Takeuchi. The series takes place in Tokyo, Japan, where the Sailor Soldiers (セーラー戦士, Sērā Senshi), a group of ten magical girls, are formed to combat an assortment of antagonists attempting to take over the Earth, the Solar System, and the Milky Way galaxy. Each Soldier undergoes a transformation which grants her a uniform in her own theme colors and her own unique elemental power. The ten Sailor Soldiers are named after the planets of the Solar System, with the exception of Earth but inclusion of its moon. While many of the characters are humans with superhuman strength and magical abilities, the cast also includes anthropomorphic animals and extraterrestrial lifeforms.
The series follows the adventures of the titular protagonist, Sailor Moon, her lover Tuxedo Mask, and her guardians: Sailors Mercury, Mars, Jupiter, and Venus. They are later joined by Chibiusa (Sailor Moon and Tuxedo Mask’s daughter from the future) and four more guardians: Sailors Pluto, Uranus, Neptune, and Saturn. The series’ antagonists include the Dark Kingdom, the Black Moon Clan, the Death Busters, the Dead Moon Circus, and Shadow Galactica.
Takeuchi’s initial concept was a story called Codename: Sailor V, in which Sailor V discovers her magical powers and protects the people of Earth. After the Codename: Sailor V manga was proposed for an anime adaptation, Takeuchi changed her concept to include ten superheroines who defend the galaxy. The manga’s anime and live-action adaptations feature some original characters created by the production staff and not by Takeuchi.