Usagi Tsukino (月野 うさぎ, Tsukino Usagi, renamed "Serena Tsukino" or "Bunny Tsukino" in some foreign adaptations), better known as Sailor Moon (セーラームーン, Sērā Mūn), is a Japanese superheroine and the main protagonist and title character of the Sailor Moon manga series written by Naoko Takeuchi. She is introduced in chapter #1, "Usagi – Sailor Moon" (originally published in Japan's Nakayoshi magazine on December 28, 1991), as a carefree Japanese schoolgirl who can transform into Sailor Moon. Initially believing herself to be an ordinary girl, she is later revealed to be the reincarnated form of the Princess of the Moon Kingdom, and she subsequently discovers her original name, Princess Serenity (プリンセス・セレニティ, Purinsesu Sereniti). In Sailor Moon, Usagi meets Luna, a magical talking black cat that is searching for the Moon Princess. Luna reveals that Usagi is destined to save Earth from the forces of evil and gives her a brooch to transform into Sailor Moon. She asks Usagi to form the Sailor Guardians, find their princess and protect the "Silver Crystal". As Usagi matures, she becomes a powerful warrior and protects her adopted home planet, Earth, from villains who wish to harm it. Usagi is depicted as usually carefree and cheerful, but with cry-baby tendencies that show themselves when things do not go her way. As the protagonist, Usagi appears in every episode, film, video game, and television special of the anime adaptations, Sailor Moon and Sailor Moon Crystal; as well as the live action adaptation, Pretty Guardian Sailor Moon. She also cameos in the sister series Codename: Sailor V. She has been the subject of parodies and has appeared in special events. Usagi's critical reception has been largely positive and she is recognized as one of the most important and popular female superheroes of all time. From Wikipedia