Played by: Miyuu Sawai
First appearance: Act 1

Usagi is pretty much just an average happy-go-lucky teenage girl. She's always late for school (she goes to Juuban Middle School), she does badly on her tests, and she enjoys singing at the karaoke bar (Karaoke Crown) with her friend Naru. Her idols are pop sensation Minako Aino and the mysterious heroine Sailor V.

One day, Usagi meets Luna, a plush toy cat who can talk. Luna tells her that she is Sailor Moon, one of the four Sailor Guardians who have to protect the princess. Along with the other Sailor Guardians who are gradually discovered, Sailor Moon's mission is to find the princess, search for the legendary Silver Crystal, and fight off the forces of the Dark Kingdom... when she's not busy being distracted by unrelated things (much to the annoyance of Luna).

Sailor Moon is sometimes helped in battle by a mysterious man called Tuxedo Mask. Sailor Moon falls in love with him, not knowing that he's really Mamoru, a jerk she keeps bumping into (quite literally in some cases), or that he's also after the Silver Crystal. The real story of Usagi and Mamoru has yet to be revealed...

Usagi means "rabbit", which is why Usagi's bedroom is full of things that relate to rabbits. Also, her full name is a play on words: In the Japanese name order it is "Tsukino Usagi", which when read aloud can be taken to mean "rabbit of the moon", a reference to a Japanese legend.

When Usagi becomes Sailor Moon, her hair turns blonde, the pigtails become longer, and the style at the top is changed slightly.