In the initial proposal for the Sailor Moon series, each of the five heroines had a completely unique outfit. Eventually it was determined that they would wear uniforms based on a single theme, and Sailor Moon's costume concept was the closest to that which would eventually be used for all the girls. The original did have some small differences, including color changes, an exposed midriff, and ribbons around the gloves and boots. She also had a mask, which would appear in a few chapters of the manga itself before being discarded. These aspects of Sailor Moon's costume are shown in multiple pieces of early artwork, along with a gun and cloak, which were also parts of the original concept.
Usagi's signature hairstyle derives from a "good luck charm" of the artist's; in college, Takeuchi would put her own hair up in odango before difficult classes or exams. In the initial sketches, Sailor Moon had pink hair. By the intermediate stages of development, Takeuchi planned to have the character's hair be blond in civilian form and change to silver when she transformed, but she was told by her editor that silver hair would be too plain for cover art. Nevertheless, stylistic use of differently-colored hair does sometimes appear in later artwork, and the concept of the heroines' hair changing color when transformed is used in Pretty Guardian Sailor Moon.
Of all the Sailor Senshi, Usagi's personality is closest to Takeuchi's own personality at the time Sailor Moon was created.
Certain background details of Usagi's character were chosen symbolically—for instance, her Western astrological sign is given as Cancer, which in astrology corresponds to the moon. In reference to a popular Japanese belief, her blood type is given as O, supposedly indicating friendliness, optimism, and carelessness.
The kanji of Usagi's surname translate as "moon" (月 tsuki) and "field" (野 no). Her given name is in hiragana usagi (うさぎ) and so its meaning is not inherent, but the word itself means "rabbit" and this is used as a pun frequently throughout the series, even in her hairstyle and possessions. Her entire name is structured as a pun, as the syllable "no" indicates a possessive, so that her name can also be understood as "Rabbit of the Moon." This derives from a Japanese folktale about the rabbit that is said to be visible in the Moon's face, much like the Western Man in the Moon. The English-language manga gives her the nickname Bunny to partially preserve this pun; many other localizations use the name Bunny as well. "Usagi" is not a common given name in Japan.
Similarly for the dubbed anime, "Serena" is probably at least in part a play on the word Selene, a moon goddess in Greek mythology who fell in love with a shepherd named Endymion. It also derives from the name of the series' moon princess, which is alternately either "Selenity" (from Selene) or "Serenity" (from the Sea of Serenity on the moon), both of which would be rendered in Japanese as [seɽeneti]. In an early DiC promotional tape that advertised Sailor Moon to television stations, Usagi was called Victoria.Another preliminary name that appeared on Kodansha's English website in an advertisement for the series was Celeste.
Sailor Mercury (セーラーマーキュリー Sērā Mākyurī), officially spelled as Sailormercury in Japan, is one of the central characters in the Sailor Moon metaseries. Her real name is Ami Mizuno (水野 亜美 Mizuno Ami, or Amy Anderson in the English versions), a genius schoolgirl who can transform into one of the series' specialized heroines, the Sailor Senshi.
