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.

During a string of disappearances of miko priestesses, Usagi runs into one of them, Rei Hino, who is the prime suspect of the missing girls. Usagi defends her reputation, until the two got pulled into another dimension by a Youma, causing Rei to awaken as Sailor Mars.

There is a rumor that the Mystical Silver Crystal will be exhibited at a high-society costume party. Tuxedo Mask decides to look for it, followed by Usagi, but the Dark Kingdom is still one step ahead. Meanwhile, Rei refuses to cooperate with Usagi and Ami, choosing to act on her own.

When Ami feels that her friendships with Usagi and Rei are not genuine, she reads a book on how to be a true friend. This causes friction between her and Usagi, and Ami gets into more trouble when she tries to defeat a Youma without calling for help.

Usagi is saved by a new girl in town from the bullies. When Usagi realizes the girl who saved her is at her school, she befriends her. The new girl, a tomboyish Makoto Kino, seems tough on the outside, but when she lets her guard down for a popular basketball player who turns out to be a Youma in disguise, the vulnerable Makoto must awaken as Sailor Jupiter to defeat him.

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.

When Tuxedo Mask reveals information of the Mystical Silver Crystal to the public to speed up the search for it, the mad rush brings a wealthy businessman to ask for Rei's protection of his gem that seems authentic. Meanwhile, Usagi fights her feelings for Tuxedo Mask after being warned by Sailor V that he is the enemy and gets in big trouble for helping him.

Usagi runs away from home and eventually winds up with Rei at her shrine. There, Luna sees a connection between the legend of Princess Kaguya and the real Moon Kingdom. Meanwhile, Zoisite formulates a plan to destroy all princesses under his hopes of defeating the Princess of the Moon.

Minako is being cared for at the Juban Hospital and Usagi and Makoto abandon the Sailor V search to visit her. Meanwhile, Rei, Ami and Luna go check out a hint on the internet about Sailor V which turns out to be a trap set by Zoicite.

Usagi aids Minako in escaping her manager and spend some quality time together. Later on, Sailor V reveals herself as Sailor Venus, princess of the Moon Kingdom.

Usagi and Mamoru help Motoki find his pet turtle, leading them to a kind hermit with no memories. Meanwhile, the evil Queen Beryl intends to awaken her fourth general, Kunzite.

Usagi faints as Kunzite's spell to transform her into a Youma comes back into affect. While Makoto and Rei run off to find Kunzite, Ami does her best to help Usagi fight back.

Usagi goes on a mission to recover Minako's stolen jewels. Meanwhile, Ami has tension with Naru but won't tell the others why.

Ami is jealous of Naru's relationship with Usagi. Meanwhile, Youma are causing people to disappear in order to steal their energy.

Usagi is overwhelmed by her feelings for Mamoru and decides to get over him by making a scarf for Tuxedo Mask. Meanwhile, Rei visits her mother's grave and runs into Minako... who she sees transform into Sailor Venus!

Rei and Minako are butting heads with each other. Meanwhile, Usagi is still distraught over Mamoru, who is about to get caught up in a youma trap with his girlfriend.

It's Valentine's Day and Usagi is babysitting a young girl with a similar romantic crisis. The two are able to use their own situations to help give the other more courage.

Hikari asks Usagi to go on a double date with Daichi and Mamoru, but they are followed by Minako and Usagi soon learns that Mamoru and Hina are engaged. Meanwhile, Rei goes off on her own and Kunzite plots to capture his own Sailor Senshi.

Usagi takes a sick day following the situation with Mamoru, but Ami is also noticeably missing from school. Makoto finds her curled up in bed and cares for her before Ami makes an odd request to go to an amusement park where she passes out! Ami is rushed to the hospital where she later escapes and makes her way to Kunzite for a startling discovery.

After the team's introduction to Dark Mercury, Usagi finds that Ami has turned their class against her. Later, Mars and Jupiter battle a Youma while Ami challenges Sailor Moon to a fight.

Rei runs into Minako during one of her monthly visits to the hospital and gets forced into putting on a performance for sick children. Now it's Usagi to the rescue, who is there to help Rei in her time of need.

Even though Usagi decided to stop thinking about Mamoru, she runs into him in the street. After learning that he's leaving to study abroad Usagi is overjoyed, but when Hina reveals that he'd possibly been attacked by someone named Kunzite, Usagi leaps into action and runs to his rescue.

After Usagi learns that Mamoru is Tuxedo Mask, Hina realizes his feelings might belong to another. Meanwhile, Kunzite has a hunch that Sailor Venus is not the real princess.

Due to Usagi's tears, Mamoru, who had been lost to the Dark Kingdom, opens his eyes. Simultaneously Luna, Mars, and Jupiter finally learn who the real Princess is. Indeed the Princess of the Moon was Sailor Moon, Tsukino Usagi!! A long, long time ago, in a previous life, Usagi was the princess of the Moon (Serenity) and Mamoru was the prince of the Earth (Endymion) and they were deeply in love. Yet theirs was a forbidden romance. The tragic destruction of both the Moon Kingdom and the Earth came about because of their relationship. But the two of them, deeply tied by fate from their previous lives, have surpassed the boundaries of time and once again met! Soon Mamoru will be leaving to London with Hina, his fiancé. What will become of his future with Usagi from now on?

Usagi and Mamoru had previously lived their lives deeply in love, as the Princess of the Moon and Prince of the Earth. Although in the present they have once again managed to meet due to their strong attraction, the love between the two of them cannot be allowed. Looking to find his true self, Mamoru has journeyed to London. Having given up on Mamoru, Usagi now decides to focus all her strength on regaining the dark-hearted Ami. Meanwhile, a single senshi appears in front of Ami. (Sailor Mercury.) Stating, ""I will surely restore you,"" who could this senshi be? And a mysterious girl also happens to appear in front of Usagi, Rei, and Makoto at the same time.

The spell cast upon Ami started to break by the light of the ginzuishou. But Ami's heart was still troubled, and as though casting off doubts, she hit Sailor Moon with her sword. When she came to, Ami found herself and Usagi in the middle of a forest. No longer cursed, Ami can still remember everything that had happened between her and Usagi through to now. Yet it is too late. Carrying the motionless Usagi, Ami bursts into tears

Ami is back to normal, and tranquility has returned to them all. Arriving at their school is a new, mysterious exchange student, Kuroki Mio. But she is a rival of Aino Minako, and also...?! Having transferred to Juuban Middle school is a new idol, Kuroki Mio. Usagi burns with hostility as the girl is ""Like Aino Minako's rival!"" And finally the two of them enter a volleyball match!

The idol Kuroki Mio, who had transferred to Usagi's class, has skillfully become acquainted with Usagi. Yet there is a rumor spreading about Usagi's classmates that ""Usagi abandoned Mio and fled"" due to what happened that time that Usagi had to go fight the youma and left Mio on her own in a safe place. Thus, Usagi becomes a lone wolf, because she is not able to tell them that she was actually fighting. [Whoever gets the Kodocha reference wins.] Making the appearance that she is Usagi's ally- but in actually attempting to ensnare her- Mio is even going to drag Aino Minako into her trap.

Makoto worries about being the only Senshi whose power has not yet been awakened, so she tries whatever she can to make it, while dealing with her feelings and Motoki.

Has Mamoru disappeared in London? Usagi can't take it anymore. And with that, Mio provides her with a heaven-sent opportunity ""You can go to London."" The question is, can Usagi dash to Mamoru's side? In that regard, wanting to go to London, Usagi finds it unbearable. In order to get to England she becomes the attendant of the popular actor Yuuto. But having played the mediator, enabling Usagi to do this, hmm... that Mio must be up to something! As it were, Mamoru flew to London like he was running away from something. But, even if he's in London, fate's not going to leave him alone. As Kunzite noted of the circumstances, ""What kind of meeting is this..."" How will Mamoru respond?

Finally, Usagi and Mamoru's affections have united. Although their love has been said to be cursed since their previous existence, seeing Usagi's delighted appearance, her friends cannot separate them, despite their personal unease. As opposed to Usagi, who's reached the summit of happiness, Ami has been always lonely due to being emotionally isolated from her mother, and Rei, with her father being a politician, has always been resentful of him. Yet the situation has presented itself in such a way that both will have to face off against their parents.

Since Ami was a child she has always suppressed herself and followed what her mother requested of her to make her mother happy. But even though her mother said it would be best to change schools, Ami is unable to suppress herself, as in the past, this one time. Meanwhile Rei remains unable to forgive her father the politician for not coming to the hospital when her mother was dying. What actions will these two, who hold such complex feelings toward their parents, take...?

Usagi and Mamoru's relationship has been prohibited since their previous existence, but the two of them- vowing that things ""won't be like last time""- begin their love anew. Given Usagi's excessive zeal, the other senshi cannot bring themselves to strongly oppose them. Yet Sailor Venus, knowing full well the horrors of their relationship, refuses to forgive it. Whilst she considers methods of stopping them, in front of her materializes Zoisite. With the same desire to pull the two of them apart, Zoisite makes Venus a proposition.

Aino Minako (Sailor Venus) lets Rei in on an important secret. While Rei, having been told such a secret so suddenly, is unable to hide her shock, she doesn't have time to lose her bearings. Their enemies are growing stronger by the minute. As Rei and the rest are staying vigilant, the Dark Kingdom's ruler, Queen Beryl, having desired Endymion since their previous existence, has finally appeared in front of him.

Usagi, having lost Chiba Mamoru to Queen Beryl, must suppress her feelings of concern for him and believe in his return. And while Luna wasn't looking, Usagi disappeared! Since the last thing Luna had heard was a harp's note, Usagi must be in her Princess form. Relying on this note, the senshi begin their search for the Princess. Meanwhile Mamoru, taken to the Dark Kingdom, faces his retainers from his previous existence, the Shitennou.

Exactly what happened in her previous existence was finally revealed by Princess Sailor Moon's very own lips. Luna and the senshi cannot easily get over something like this. Meanwhile, having heard from Queen Beryl the truth, Mamoru strengthens his resolve. ""I destroyed the planet...."" With these words, Princess Sailor Moon disappears once again. Inside her heart, she is facing off against ""Usagi"" but... ""The Princess' existence is surely call for calamity to this planet!""

Facing Sailor Moon, Mamoru- as his previous-existence alter-ego Endymion- drew his sword! With the intention of not repeating the tragedy of their previous life, Endymion declared war upon Usagi. But Usagi's feelings will not change. She will gallantly continue to believe in Mamoru. Also, in a completely unexpected twist, Aino Minako's office president requests Usagi's mother to become a television reporter! (I prey they change this and get a nicer one)

Having been taught by Mamoru that the only way to protect the planet is to do it oneself, Usagi seeks to harness the power of the legendary Silver Crystal. Meanwhile Minako decides that, given how little remaining life she has left, she will quit singing and focus only on the completion of her previous existence's mission. Just as she is about to does this, she is informed by the office president that Minako's work will be taken over by a new face. Having suddenly snapped away her work, the identity of this new idol who appears before a surprised Minako is...

As they enter summer vacation, some volunteer work pops up at Usagi's school. With her classmate Naru, Usagi, Ami, and Makoto help watching over kids at a children's home. While she doesn't know how to handle the kids, Usagi's got a particular scheme in mind. Without telling Makoto, she calls up Motoki and leaves the two alone. Not knowing anything, Makoto carries the children's dirty clothes to the backyard. ...where Motoki has just arrived.

Naru enters a coma after Princess Sailor Moon awakens again. Usagi conjectures that negative emotions fuel her power, so she tries her best to suppress such emotions.

A life-taking stone has been implanted into Mamoru's body by virtue of Queen Beryl's trap. The more he loves Usagi, the closer he creeps to death. Knowing this, Usagi's anger rises. And with that Usagi changes... Having realized this change, Mamoru is determined to meet Usagi, regardless of the stone's existence within himself. His grace period is until sunset, and if he doesn't return Queen Beryl will take his life.

Rei and Minako antagonize over their reactions of their previous life. Rei asserts that Minako- having never awakened her senshi powers- has no qualifications to fight, but that's because she has something in her mind. Meanwhile, coming to the conclusion that no matter how much she hopes it would happen, she'll never have Endymion's heart, Queen Beryl at last comes to the decision to take the Princess's life.

Sailor Venus has collapsed at last. Makoto and Ami begin to notice that her condition isn't exactly normal. While Artemis is desperately recommending surgery, Minako- who's been living only to see her previous life's mission completed- doesn't want to listen to him at all. And of course at this time a youma appears. Makoto's heart is struck by Venus' attitude of putting her life on the line to see her mission to its end, and goes off her rocker.

Having seen Makoto become willing to throw her life away to complete her mission, Minako reflects on her own captivity to her past. Meanwhile, Rei, arriving at the Dark Kingdom thanks to Mio, meets with Mamoru! ""Even if it costs me my life, I'll see my mission to the end!""

Venus finally finds success in awakening her senshi powers and defeating the youma. And she decides to be operated on. Her friends the senshi, believing the operation will work out fine, plan a party. With a smiling face Minako heads toward the operation's inspection... Even though the odds are slim, Minako decides she's going to do the operation. And so that day comes a calling. The five of them beat the strongest youma; Naru, Motoki, and the other victims have returned to normal and the town's peace has been restored

After school Usagi is walking home to find Mamoru standing on the other side of the bridge, they walk up to each other and he hugs her, then she starts crying out of happiness. later Mamoru kills Kunzite and turns into Dark Endymion meanwhile the other Senshi are fighting an Younma and some how they end up get attacked by Endymion. whilst the other Senshi are fighting the Younma Mio gets killed by Endymion and after the other Senshi were attacked he aims at Usagi and hits but Usagi turns into sailor moon. After sailor moon henshins (not exactly) she has a sword and Mamoru tells her to attack sailor moon looks at him and decides she will do so. in the end Usagi kills Endymion and whilst shes get her run up Makoto, Ami and Rei yell at Usagi not to do it but Usagi doesn't listen because she knows what she must do

After Sailor Moon has no choice but to kill Endymion, the Princess uses her power to destroy the world again, and the other Senshi are too late to stop it. Realizing that the world's demise was, in fact, the result of her selfishness, Serenity uses again the power of her love for Endymion to bring the world back to its original state, giving Usagi and Mamoru a second chance in life.