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.

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.

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.

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?

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?

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!""

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!""