Usagi dreams of Endymion and hears Mamoru calling her Usako. She wakes up. The pocket watch has stopped moving again. She wonders if that's a sign that Mamoru is safe.
Outside, Usagi bumps into someone and falls. When she looks back, she sees the man who bumped into her. He looks a lot like Mamoru. She dismisses it as coincidence and picks up the pocket watch that she dropped. It's moving again.
Motoki and his friend Endou are walking home from school. Endou is teasing him about a girl named Reika, so both do not notice that there is a man standing by the Game Center. The man asks Motoki if her works there, and Motoki assumes that he is answering the help wanted ad. Motoki explains that his father owns the building and introduces himself. The man takes off his sunglasses; it's Endymion. Motoki recognizes him as a younger student who's been hanging around Usagi. [note: Motoki is in his first year of college, while Mamoru is a junior in high school] Endymion reacts to the name "Usagi."
Motoki signals for Endou to go inside without him. A beam of light from Endymion's eyes strikes Endou and vaporizes him. The light then shines in Motoki's eyes. "From now on, I am your best friend, Endou. Nice to meet you."
Reika goes to the Game Center to return a book to Motoki. Motoki, now with blank white eyes, introduces Endymion as Endou. Reika is taken by surprise and drops her books on the floor. One book, an encyclopedia of precious stones, falls open. Endymion stares at it, and Reika describes four stones to him: jadeite, nephrite, zoisite, and kunzite.
After school, Usagi, Ami, and Makoto collect "V-chan" (as Usagi calls her) and Rei. Together, they go over to Ami's house to study the sword. The sword easily chips one of Ami's mother's diamond rings. Ami determines that the sword is petrified and very toxic. while the girls discuss the final moments of the Moon Kingdom, Usagi falls asleep. Makoto carries her into Ami's room and tucks her into the bed. Discussions about the sword continue without her.
Usagi wakes up remembering the time she woke up in Mamoru's bed. She slips out of Ami's house and goes to the Game Center. Inside, she sees Motoki and... Endymion. Endymion remarks on the similarities between Usagi's odango and Sailor Moon's. Motoki introduces Endymion as Endou. The ruse is completed when Endymion says he is a freshman at K.O.. University. Usagi is inclined to believe him. Endymion asks Usagi to teach him how to play the Sailor V game.
Back at Ami's house, Minako gets an urgent call from Artemis. Someone is clearing the stages of the Sailor V game much too quickly. The girls run to the Game Center and see Endymion playing. They are stunned, but Rei recognizes that the man is not the real Mamoru.
The next day, Usagi blows Naru off in order to see Endymion at the Game Center. Luna warns her that the man is not Mamoru, but Usagi insists she knows that.
At the Game Center, Endymion and Motoki notice that the stages of the Sailor V game keep coming infinitely. When Usagi arrives, Endymion sits her down at the console. Endymion notices her odango again and asks her if Sailor Moon and Sailor V have a command center. Frightened, Usagi runs out of the Game Center. Endymion is upset that Usagi is able to resist his suggestions.
Makoto and Ami run into Reika outside the Game Center. They question her about Endou. Reika says that she's in the same clique as Motoki, but that the old Endou was a geeky guy; she doesn't know who this Endou is or where he came from.
Endymion and Motoki walk down the alley behind the Game Center. Endymion is convinced it will lead him to the Command Center. Makoto sees them and confronts Endymion.
Usagi, Ami, and Minako run into the Command Center. Makoto tells them that she has information on the fake Endou. She says that he is an enemy who wants the Ginzuishou. Usagi is reluctant to believe her, and shows Makoto that she always carries the Ginzuishou on a chain around her neck. Makoto's eyes flash and she reaches for the crystal. An alarm sounds in the Command Center.
Makoto tries to grab the Ginzuishou, but Minako kicks her in the stomach. Endymion, dressed as Tuxedo Kamen, and Motoki enter the Command Center. The Senshi (except for Usagi) transform. They try to hold Endymion back, but a beam from his eyes strikes the Ginzuishou, lifting it away from Usagi and delivering it to his hand. Usagi sits on the floor in shock.
Luna tries to help by jumping on Endymion, but he picks her up and flings the cat against the wall. Luna falls in a pool of blood. Horrified, Usagi transforms and uses her powers to heal Makoto and Luna. She then turns on Endymion, but Beryl appears beside him. "Princess Selenity, will it make you happy to be killed by Prince Endymion?" she laughs.
Queen Beryl explains how she used the power of Queen Metallia to resurrect Endymion's dead body. Sailor Moon is having trouble accepting what she is hearing. Endymion raises his hand and blows the roof off the Game Center. Sailors Mercury and Jupiter take the now cured Motoki outside. He recognizes the two as Ami and Makoto.
Back inside, Beryl's hair wraps around Sailor Moon's neck, choking her. Beryl demands to know the secret of the Ginzuishou, but Sailor Moon does not tell her. Sailor Venus remembers Beryl from the time of the Moon Kingdom.
Beryl manipulated the people of Earth and led an uprising against the Moon. She was the one who killed Prince Endymion. In turn, Beryl was killed by the past Sailor Venus.
Sailor Venus warns Queen Beryl that she is being used by Metallia. Instead, Beryl says that she will not allow Metallia to rule; she will keep the Ginzuishou and Endymion for herself. Sailor Moon hears this and cries out for Endymion.
Sailor Venus uses her Love Me Chain to try to free Sailor Moon from Beryl's hair, but nothing is working. Frustrated, Sailor Venus holds out her hand and calls for the sword. It appears, but she cannot lift it. Sailor Jupiter takes it and cuts through Beryl's hair, freeing Sailor Moon.
Sailor Venus grabs the sword and calls out to the Moon for strength. She raises the sword over her head and rams it through Queen Beryl's stomach. The dark casing on the blade shatters, and the sword shines. As she dies, Beryl remembers how she was jealous of the Prince and Princess. Her body melts.
Sailor Venus reads an inscription on the sword: "'When this sword shines... Hidden within she who is the Queen, the Ginzuishou shall stir as does that spirit. Carrying that, it will waken completely the great power of the Moon. Pray to the sacred tower of the Moon for peace in our kingdom once more.'" Venus passes out. Endymion grabs her and carries her and the sword through a portal. Sailor Moon follows.
Using the computer, the Senshi discover that the Dark Kingdom's base is at D Point in the Arctic Circle. They teleport to the area. Luna tries to lead them via the computer in the Command Center, but she loses contact with them.
In the castle of the Dark Kingdom, Sailor Moon tries to make Endymion remember her. "It's me. Selenity." He walks towards her and touches her face. Suddenly, he grabs her by the neck and demands to know why the Ginzuishou is not giving out any power. He squeezes tighter, and Sailor Moon reaches for the Ginzuishou in Endymion's other hand. As she touches the crystal, it flashes, knocking her to the ground.
The Senshi arrive in the room just in time to see Metallia enter. She is after the Ginzuishou. As she advances, Endymion attacks the Senshi. Understanding that it is not the real Mamoru, Sailor Venus tries to kill him with her new attack, Rolling Heart Vibration, but it fails.
Distraught, Sailor Moon picks up the sword and runs towards Endymion. The sword pierces his chest. His eyes clear, and she kisses him. Sailor Moon then takes the sword and thrusts it into her own chest.