Mio gloats about Usagi becoming Princess Sailor Moon again.
Queen Beryl orders Jadeite to insert a stone into Mamoru’s body.
The senshi discuss the recent youma attacks. Usagi believes that it’s her fault because she can’t control the Ginzuishou.
Usagi visits Naru in the hospital. Naru is a little angry the Usagi didn’t tell her about being Sailor Moon earlier.
Kunzite practices his sword fighting and discusses what is happening with Zoisite. Zoisite asks Kunzite if he will break the curse on himself (Kunzite) but Kunzite informs him that his quest for revenge is his own will.
Usagi fully explains what has happened, and Naru tells her that she’s sure that Usagi can prevent Serenity from destroying the Earth.
Usagi starts a “training” regimen. First she sits in a hot bath for three hours before passing out. Luna discovers her, but gets caught by Shingo, who decides he’s seeing things. Mama thinks that Usagi is on a diet, and tells Usagi that she’ll be all right since she inherited Mama’s body.
The extra-strong youma reappears.
Motoki comments on how mopey Nephrite is. Ami shows up at Crown and is surprised to find Usagi continuing her endurance training by overheating their hideout. The other girls eat sherbert and use fans while Usagi bundles herself and tries the difficult math and science books that Ami brought her. Makoto brought some foods Usagi hates, but before Usagi can eat them, she faints again. When she revives, she tries again, even more determined.
Jadeite prepares to attack Endymion, but he hears Zoisite’s music. Jadeite remembers part of the past where the Shitennou and Endymion are playing around. Beryl stops Zoisite before he can fully awaken Jadeite’s memories, and Jadeite successfully attacks Endymion.
Ami and Usagi are on the way to the hospital when Luna senses a youma. They rush in, but the youma isn’t there, and all the patients have collapsed. The three run outside and confront the youma. Sailor Moon and Sailor Mercury attack, but the youma powers-up somehow. It attacks back, and Mercury is visibly injured.
Sailor Moon is upset and while she struggles with Serenity, Endymion steps in to fight the youma. Mio appears and threatens Endymion before Beryl hits him with some sort of energy from the Dark Kingdom. Mio explains about the stone inside Endymion. It only drains him when he’s thinking about Usagi. She then teleports away with Endymion.
When the youma attacks again, Sailor Moon can’t surpress Serenity. When she powers up the Princess Sword to attack, the nearby plants start dying and people collapse.
Nephrite senses the power from Crown and recognized it as Metallia’s.
When Serenity sees Mercury fall again, Sailor Moon breaks out for a moment and she turns her sword into her Princess Harp and heals her and the flowers recover. She then prepares to do her Star Attack. Usagi’s personality comes through and the attack backfires, hitting her.
Usagi tries to explain that Serenity’s power hurts the Earth, but Serenity only wants to know about where Endymion is. Serenity tells Usagi that the only person who cared about her as a person was Endymion and there’s no reason to save the Earth if Endymion isn’t there.
In the end, the force of Usagi’s personality wins out, but not before Serenity warns Usagi that Usagi will someday destroy the planet for Mamoru’s sake.
The youma is not destroyed by the three senshi’s simultaneous attack and flees. Usagi wonders whether it can be beaten without the power of the Ginzuishou.
Mamoru collapses in the Dark Kingdom, and his form begins to appear in a painting on the wall.