Sailor Mercury is fighting a youma alone at night in the city. The youma blasts her with a spray of water, which she nimbly dodges. Mercury tells the youma that using water to fight her shows real guts, and then performs "Mercury Aqua Cyclone!" on the youma. The youma simply absorbs the attack and throws it back at Sailor Mercury, who falls into a fountain.
Suddenly, Sailormoon appears and begins to fight the youma. Mercury is concerned that Sailormoon is fighting, but also grateful. The youma flees, disappearing. Sailor Mercury thanks Sailormoon, and Sailormoon comments that there are more Youma these days. Sailor Mercury agrees.
Back at the Karaoke Crown base, the senshi meet and discuss Usagi. Makoto observes that although Usagi doesn't know where he is, she still wants to rescue Mamoru with all her heart. Ami comments that although Usagi has been depressed lately, she is also doing well to suppress the Princess. Luna tells them that the real problem they have is dealing with the victims of Queen Metallia, and that the ginzuishou can't even help to revive them. Rei asks her if there is any way to help them, and Luna replies that defeating Metallia is the only way, and that the large youma that fled worries her, noting that it had a different power and feel to it than other youma, so it might be linked to Queen Metallia. The senshi agree that they should try to find and defeat that particular youma first, because without Metallia, they would be able to utilize the ginzuishou's powers.
At the Dark Kingdom, Jadeite is approached by Zoisite. Jadeite begins to walk away from Zoisite, telling him that he has nothing to say to him, but Zoisite pushes him roughly against the wall and begins to criticize him for what he has done to Mamoru, saying that Endymion is his master. Jadeite responds that it's different now, and pushes Zoisite away, declaring that Queen Beryl is his master by choice.
In the throne room, Beryl begins talking to herself. She says that before she was always missing something, but it was different now. She says that if the Princess takes Endymion's heart, he will become hers eternally.
Meanwhile, Usagi sits in her pajamas on top of her bed, staring at the Moon Phase. Luna approaches her and asks her why she's awake. Usagi responds that Queen Beryl loves Endymion, and wonders why she's doing that to him, that it is cruel. She grips the moon phase tightly and the moon outside turns a bloody red. As she sleeps, Usagi's body begins to pulse with light.
The harp's music begins to play, and Mamoru awakens sharply saying "Usagi!" Queen Metallia also begins to pulse with energy, and Queen Beryl remarks "Princess!"
At the city, Princess Sailormoon plays her harp on a building rooftop. Luna rushes over and grips the harp, calling "Usagi-chan!" over and over until finally, she turns back into Usagi from Princess Sailormoon.
At the Dark Kingdom, Queen Beryl watches as the energy fades on Queen Metallia, but says that even if she has calmed down, at this rate Queen Metallia will have too much energy and even if she rules the world, the planet would be destroyed. Mamoru approaches her, and tells her that he will go to the Princess. Queen Beryl asks him if he finally understands that he needs to eliminate the Princess, and Mamoru tells her that he won't eliminate her, but he can suppress her if given the time. He asks Beryl to stop the power of the stone that is inside of him. Beryl tells him she will not, that he is hers and then asks him if he understands why she is taking his life, that it is because she will never again lose him to the Princess. Mamoru tells her he will definitely return, and that if he had wanted to run before... Queen Beryl won't hear it, and tells him to go back to his room before lifting her hand and sending him there with dark energy herself.
At the Tsukino residence, Ikuko-mama asks Usagi how her boyfriend has been lately. Usagi doesn't answer, instead looking at her feet. Ikuko continues to babble, saying that she should bring him over to the house next time and she'll cook a feast for him. Usagi agrees with "Sure, next time." She gets up to leave, and Ikuko is surprised because she hasn't eaten everything. Usagi tells her that she didn't get a lot of sleep last night and she is going to take a nap. Ikuko starts to protest, but Usagi leaves.
At Crown Karaoke, the senshi discuss Usagi's situation, realizing that if Usagi sleeps, the Princess takes advantage and appears. Luna agrees that Usagi can do her best when she's awake, but no one can fault her for being defenseless sleeping. Ami asks if it's because of Endymion, and Luna agrees that it is probably because his life is in danger. Makoto asks if that's why Usagi is that way, and Luna tells the girls that Usagi didn't really sleep and she told her to go to her room. Ami tells them all that if Usagi was the only one who needed to work hard, then they wouldn't be there. Makoto states that protecting the Princess is their mission. Rei gets mad at this statement and tells Makoto that they don't protect her because she is the Princess, that it has nothing to do with the mission at all. Makoto asks her how could it not be related, and Rei declares that she's had enough of the past life stuff.
Alone in her room, Usagi thinks about her mother's request. She wonders why her situation is this way, and lays back on her bed. The harp music plays again, and Queen Metallia begins to pulse with energy once more.
The Metallia youma appears in the city, causing people to collapse all around.
At Crown, Luna suddenly jumps up and tells the others she hears the sound of the Princess's harp. The girls are alarmed.
Minako, meanwhile, runs through a building in which everyone was attacked, and are collapsed on the floor. She continues to run through the building after pausing briefly.
Mamoru stares out the window of his room, and notices the change as well. "Again?" he asks. Mio approaches from behind him and tells him that he can go to the Princess, and that she'll stop the power of the stone for him. However, she tells him, is that this will be the last time he can see the Princess.
Luna, Rei, Makoto, and Ami run along, searching for Princess Sailormoon. They stop when they see all the people collapsed and drained. The girls look up and see the Metallia youma ahead of them. Luna identifies the youma as being the one they need to destroy, and the senshi transform. They do their introduction phrases, and the youma, unimpressed, simply turns and walks away. The senshi run after it, but some golem youma appear and they are forced to deal with them first.
Near the sea, Princess Sailormoon sits playing her harp. Mamoru approaches her, and calls her name. As Princess Sailormoon sees him, she transforms back into Usagi. Behind Mamoru, Mio follows. She tells Usagi that she brought Mamoru for her. Usagi asks Mio if she's with the enemy, and Mio tells her that's scary and grips Mamoru's arm. Usagi glares at Mio, knowing that she isn't being entirely truthful, but Mamoru continues to walk up to her, grabs her hand and tells her to forget it. Mio continues to follow behind, so Mamoru turns around and says "There's no need for you to follow, right?" leaving Mio alone. She agrees that that's fine, but that Mamoru shouldn't forget his promise.
As Mamoru and Usagi drive off on his motorcycle, Mamoru thinks back to the deal he made with Beryl. Beryl tells him that he will return at the end of the day, no matter what, and that if he returns Queen Beryl will destroy the stone that is within him. Usagi is, meanwhile, confused. She doesn't understand why Mamoru is being allowed to be with her, and even questions if it is really Mamoru.
The Senshi continue their battle with the golem youma. Just as Sailor Luna defeats one, a larger youma appears behind her and grabs her. As Sailor Luna struggles, and the other senshi are engaged in battle and cannot help, Sailor Venus's love-me-chain attack comes through and whips the youma away from Sailor Luna. Taking control of the situation, Venus tells the senshi to disperse so they can more easily destroy the youma. The girls spread out, and Mars heads towards Venus, telling her privately "Didn't I tell you not to fight again-" with Venus interrupting her and telling her it's no time for talking. Venus moves away and continues to fight the youma, leaving Mars to look on.
Mamoru stops his motorcycle on the same beach that the two shared a treat with in Act 13, the first time they really got along. Usagi finally asks what she's been thinking, why was Mamoru here, wondering what about the stone that is taking his life, and showing her concern for his safety. Mamoru lies and tells her the stone is gone already. Usagi tells him that she is doing very well suppressing the Princess. Mamoru asks her what it was just now, then, when he first approached her. Usagi tells him that although she is doing her best, she is the Princess... Mamoru begins to speak with her, but the water youma from the beginning of the act jumps out of the ocean, ready to do battle.
Usagi sees the youma and transforms. The youma throws an attack at Sailormoon and Mamoru, knocking Sailormoon to the ground. Mamoru runs to her side and asks if she's all right. Usagi glares up at the youma, and Mamoru wonders why now a youma should appear. He runs towards the youma, who throws out another attack. As the smoke clears, it appears Mamoru has changed into Endymion and continues to charge the youma. He begins to swing his sword at it, but the youma dodges the blows easily. Suddenly, the youma jumps up and lands next to Sailormoon, choking her. Endymion throws his sword at the creature, and struck, the youma releases Sailormoon. Sailormoon grabs the sword, left sticking up in the sand, and goes after the youma. The youma throws attacks at her, but she continues to charge with the sword. She drives it into the youma's center, and Sailormoon says "Unforgivable youma, Queen Beryl!" and begins to glow with the power of the ginzuishou. At the Dark Kingdom, Queen Metallia begins to glow with power as well. Endymion rushes over to her and tells her to calm her heart down. Realization dawns on Sailormoon and the energy begins to fade.
Meanwhile, the senshi are still in their own battle. Sailor Jupiter lets out an unnamed attack, and the other girls also battle with their respective powers. As they battle, Sailor Venus begins to faint, falling backwards. Sailor Mars rushes over and catches her, chiding Sailor Venus for fighting when she is so sick. Venus shakes her off and approaches the main youma (the one that attack Sailor Luna earlier). Venus orders the others to do a simultaneous attack on the enemy. They all power up, and aim for the youma, blowing it away.
On the beach, Endymion fights the water youma. weakening it and then calling for Sailormoon to finish it off. Sailormoon uses her "Moon Twilight Flash" attack and the youma is blown back into the ocean. Endymion stares at the setting sun, knowing his day is almost over. He turns to Sailormoon and she looks at him questioningly. He reaches over and embraces her tightly, telling her to listen carefully. He tells her that the one strengthening Metallia was the not the Princess today, that it was her. Usagi's eyes widen at this revelation, and Endymion continues to tell her that her feelings of anger and hatred are sent to the ginzuishou, and that if she lets Beryl or anything else bring forth her former personality (the Princess- selfish, angry, etc) it will effect it. He tells her that no matter what, she should smile. He tells her to act like a fool. Sailormoon tells him that she's okay with acting like a fool, but then says he's not back for good yet, is he? Endymion turns away and watches the sun set. He tells her not to worry, that his feelings can not be separated from her, that his heart will always be with her. He turns to her and they kiss ♥ just as the sun sets completely.
At the Dark Kingdom, Queen Beryl observes this with anger and jealousy, noting that the sun has set. She then says "Endymion... you would refuse me to the point of throwing away your own life?!"
In the darkness, Usagi and Mamoru splash around the beach together, laughing and kicking the water up. Zoisite and Kunzite observe them from several yards away, and Kunzite tells Zoisite that it's the second time he's thrown his life away for the Princess. Kunzite continues to say that nothing has changed, and that next he'll abandon the planet. Kunzite walks away, leaving Zoisite alone to watch, smiling.
At the Dark Kingdom, Mio sits in Mamoru's room, observing that she tried to give him a chance to save himself. She glances up to the painting and sees the energy staining it.
Mamoru and Usagi sit together on the dark beach, smiling. Usagi glances over at him, and suddenly he fades away, back to the Dark Kingdom. Usagi is left alone. Her face begins to fall a bit, but she breaks into a huge grin instead, and turns to stare at the ocean.
Meanwhile, Minako stands slightly apart from Rei, Makoto, and Ami. She asks Rei what the meaning of this was, and Rei tells her she does not acknowledge her as the leader. Minako asks her why, and Rei remarks that it is because she hasn't awoken her powers as a senshi yet. She then tells her she will not fight with such an amateur, and the girls glare at each other.