Usagi Tsukino is a 14-year-old junior high student who unexpectedly becomes a heroine after a black cat, Luna, awakens her as Sailor Moon in order to save the world. First, she must save her friend, Naru Osaka, from an evil Youma inhabiting her mother's body.

Ami Mizuno is the highest ranked student in Usagi's class, and Usagi manages to befriend her despite their academic differences. But when Luna suspects that Ami might be Senshi as well, Ami also suspects that as the reason for Usagi's friendship and refuses. When she is attacked by a Youma, Ami realizes how true a friend Usagi is and awakens as Sailor Mercury.

Usagi suspects that a Karaoke Crown attendant named Motoki Furuhata is Tuxedo Mask when she discovers a tuxedo jacket with a hole in it like from the battle the night before, and impulsively brings him a gift. Makoto and Rei are invited along with them to an amusement park where they meet two of Motoki's friends - one of which is Mamoru Chiba. Things go well until a Youma attacks Rei, and Usagi unknowingly reveals to Mamoru that she is Sailor Moon.

Rei and Makoto get into a petty argument and when arriving to apologize, Makoto thinks Rei is being kidnapped. Meanwhile, Usagi works very hard for a mascot costume contest for pop idol, Minako Aino, and is attacked by Jadeite at the contest.