Usagi Tsukino was just a normal schoolgirl, living with her parents and her brother, Shingo. Her biggest worry was trying to pass her classes. On the way to school on day, she came across some boys picking on a cat. She yelled at them and they ran off. The cat had a bandaid on its head, so Usagi pulled it off and found a golden crescent mark under it. Usagi went on to school and was late again, and also got a bad grade on a test. She talked with her friends, Naru and Umino, about jewelry and the heroine Sailor V, who'd been popping up around town. Naru's mom owned a jewelry shop called Osa-P and was having a sale, so Naru invited Usagi.
Meanwhile, the Dark Kingdom, led by Queen Beryl who was under the control of Metallia, was preparing to unleash their plans. They were trying to gather energy and find the ginzuishou (silver crystal) so they could take over the galaxy. Beryl sent one of her Shitenno (Four Kings), Jadeite, to go collect energy.
Usagi and Naru went to the jewelry store and found the prices marked down dramatically. Usagi runs into Mamoru Chiba, who comments on how awful her grades are. Usagi goes home, while Naru finds out her mom has been replaced by a youma sent by Jadeite. Usagi is very surprised when Luna comes to her house and starts talking to her. Luna gives her a compact and tells her the phrase she needs to know in order to transform.
Usagi goes to the jewelry store, transforms into Sailormoon, and battles the youma. Tuxedo Kamen shows up with an unusual speech that is apparently meant to encourage her, but ends up sounding really foolish. Sailormoon uses her Moon Tiara Action to the defeat the youma.
For awhile, Sailormoon has to fight youma by herself. Usagi goes to school one day and meets Ami Mizuno, a bright student who's just transferred here. During Ami's computer class, a youma attacks, and Ami becomes Sailormercury. Not long after that, Ami and Usagi go to a temple and meet Rei Hino, who becomes Sailormars. Usagi wonders who Tuxedo Kamen could be, and continues to argue with Mamoru. For awhile, Usagi thinks Tuxedo Kamen might be her friend Motoki who works at the arcade.
Beryl is growing increasingly frustrated with Jadeite's failures, since the Sailor Senshi always manage to stop his youma before good amounts of energy can be gathered. Every battle, Tuxedo Kamen also shows up. Beryl gives him one last chance-- kill these Senshi, or be sentenced to Eternal Sleep. Jadeite puts a hologram of himself over the city and announces that the Senshi must come to the airport at one that night. If not... he shows an image of the city burning on fire. The Senshi go to the airport, where Jadeite sends planes to try to run them over. Tuxedo Kamen attempts to intervene, but is hurt badly and can't do anything to help the girls. They attack Jadeite, and he's forced to return to the Dark Kingdom, where Beryl carries out the sentence.
The next Shitenno, Nephrite, takes over Jadeite's role. He uses his knowledge of the stars to select specific targets and youma to attack them. He appears on Earth in the persona of Masato Sanjoin, in order to keep close to the victims. He places his symbol on an item that the victim keeps close to them. After awhile, their energy reaches its peak, and he sends a youma to collect it. The Senshi are able to stop him each time. Naru starts to fall in love with "Masato", unaware of his double identity. Zoisite and Kunzite, two other generals, start getting on Nephrite's case, particularly Zoisite. Beryl is tired of Nephrite's failure to answer her summons and decides to let Zoisite take care of the situation. Usagi warns Naru that Masato is really an evil man, but she doesn't listen. Zoisite decides to make Nephrite give him the crystal he uses to pinpoint victims. Nephrite refuses. He and Naru spend more time together, and he starts to fall in love with her. Zoisite attacks him in a park and his youma kill him.
Zoisite takes charge of the mission, but his mission is to find the nijizuishou (rainbow crystals) to summon the champion warriors of the Dark Kingdom together. Not only that, but when the seven nijizuishou join together, they form the ginzuishou. Zoisite starts to search for the holders of the nijizuishou.
A girl named Makoto Kino shows up at Usagi's school. She's been transferred for getting into too many fights. Usagi makes quick friends with her and introduces her to "smart Ami-chan and nasty Rei-chan". They are walking together and come across a guy named Crane Joe who always wins crane games. Makoto is instantly smitten with him, saying he reminds her of her senpai. Zoisite attacks Crane Joe and takes the nijizuishou out of him. He becomes one of the warriors. Makoto becomes Sailorjupiter after Sailormoon shows up. They stop Crane Joe and heal him.
After Zoisite has attacked all the crystal holders, he ends up only acquiring four of them, while the Senshi have one and Tuxedo Kamen has two. He and his lover--the last of the Shitenno, Kunzite--talk about trying to get all the nijizuishou.
Luna summons the Senshi together one night after a talk through an arcade game with a being that's supposed to know all about their mission. She tells them that she was sent here to awaken them as senshi, that their used to be a kingdom of the moon, and that the princess they needed to find was the princess of the moon.
The Dark Kingdom plots to get the nijizuishou from the Senshi. An imitation Sailormoon starts popping up around town saving people. Usagi gets very frustrated about this. They eventually find out that it was a plot by Kunzite, and Zoisite (who was the imitation) confronts Tuxedo Kamen, injures him, and knocks off his mask, which for some reason is of great surprise to Queen Beryl. When the Senshi are captured, someone appears to help. It was the idol Sailor V, but when she took off her mask, she turned into Sailorvenus. She saved them, and when Sailormoon looked at her, she realized she was Sailor V. A white cat appeared and said she was Sailorvenus. Luna recognized him as Artemis. The Senshi think Venus is the princess, but she just smiles. The girls planned to meet at the shrine the next day, so the senshi showed up and met Minako Aino, who was Venus's real self.
Beryl told Kunzite and Zoisite that they had to get all the nijizuishou back, but they couldn't kill Tuxedo Kamen. Zoisite was furious. He went to Mamoru's apartment and challenged him to come to the Starlight Tower to duel for the nijizuishou. Mamoru accepted. On the way to the tower, he came across Usagi. She hit him on the back and was surprised to get blood on her hand. She followed him and was captured in an energy field. The senshi go to the Starlight Tower to find Usagi, since she hadn't been answering her communicator. Mamoru and Zoisite meet in a room. They both put their crystals on the floor while Usagi looks on. Kunzite then appears and takes the crystals. Usagi and Mamoru run to an elevator. They get in and start to travel upwards. They talk on the elevator. Usagi asks why he wants the crystals, and he explains that he needs them to get his memories back since he was in a car wreck that killed his parents when he was six and has had amnesia since. He thinks that the ginzuishou will help somehow. Zoisite plans to kill them in the elevator. Having no choice, Usagi transforms. Mamoru is shocked. They get off the elevator and battle Zoisite. Mamoru becomes Tuxedo Kamen and is injured even worse by Zoisite. The senshi arrive too late. The nijizuishou fly into the room and become the ginzuishou. Sailormoon becomes the Moon Princess. She and Mamoru remember that they were Princess Serenity and Prince Endymion in their past life.
The two Shitenno return to Beryl and bring Tuxedo Kamen with them. She is furious that they lost the ginzuishou and that Zoisite tried to kill Tuxedo Kamen. He begs for one more chance, but she throws him back and mortally wounds him while Kunzite looks on. Kunzite takes him back into his room. Zoisite asks to die pretty, so Kunzite makes some rose petals appear. Zoisite thanks him and tells Kunzite he loved him, and dies.
The senshi try to escape the Starlight Tower, but the grief stricked Kunzite is quick to attack them. The other senshi protect Sailormoon while she tries to work up the will to fight. Finally, she is able to use the ginzuishou and stop him from killing them.
Beryl corrupts Tuxedo Kamen and turns him into an evil version of his former self, Prince Endymion. Kunzite continues to try to take the ginzuishou back, while Endymion also tries to accomplish the same task. One day, Sailormoon almost manages to heal him and turn him back into Mamoru, but then he is taken back to the Dark Kingdom again.
The Senshi find a way to get to the Dark Kingdom through an arctic region. While they are there, they split up from the cats and are thrown into a sort of hallucination. Queen Serenity, mother of Princess Serenity, tells them of their past in the Moon Kingdom, and the war with the Dark Kingdom where she sealed off everyone and sent them to the future after they were killed. After returning to the present, they are attacked by Kunzite. Sailormoon kills him by repelling his own attack at him. They return to Japan.
Not long after, they use "Sailor Teleport" to journey back into the Dark Kingdom. Beryl sends five of her most powerful youma to kill the Senshi before they can reach her. One by one, all but Moon are killed fighting them; first Jupiter when protecting Moon, Mercury when she goes off alone, Venus protecting Moon, and then Mars confronts them. During this, Moon offers a number of times to give up the ginzuishou so her friends can live.
After they've died, Moon is comforted by their spirits, who tell her to go on and fight. She takes off running for the Dark Kingdom. While there, Beryl tries to make the evil Endymion kill her, but Moon heals him. Beryl then tries to kill Moon, but Endymion shields Moon with his body and dies.
Beryl goes underground to Metallia, where she is transformed into an enormous creature. Moon becomes Princess Serenity and fends her off her energy attacks with the ginzuishou. The spirits of the Senshi appear to help her. Putting all her power into the ginzuishou, Serenity kills Beryl, then dies. The light of the ginzuishou continues to expand and engulf everything. Her voice whispers that she wants a normal life again....
Usagi wakes up for school and realizes she's late. She rushes off, and the other senshi are also shown preparing. She hits Mamoru with her bad test accidentally, and tells Naru about her strange dream where she met her prince and won him.