In the Dark Kingdom, Queen Beryl fumes some more about Sailor Moon appearing. She gives Jadeite a youma stone to use to gather energy, and then tells him that if they continue to gather energy, they can destroy Earth.
Luna and Usagi visit their Crown headquarters for the first time, where Usagi proceeds to ignore what Luna says. What Luna tells her is that the mission of the senshi is to seal away the evil power that is awakening. To do that, they must find the princess and the ginzuishou.
Back at school, Usagi discovers that her grades are horrible, while Naru is ranked fifteenth and the class genius, Mizuno Ami, is ranked number one, as always. While Ami is incredibly smart, she does nothing but study and has no friends. She eats lunch on the roof, and that is where Luna realizes that Ami is probably Usagi’s companion.
Later in the day, Usagi tries to befriend Ami and lets her borrow a copy of Aino Minako’s new album. Ami does not want to become a senshi, both because she’s shy and because she spends so much time on her studies.
Meanwhile, Mama signed Usagi up for cram school. On the way there, she runs into Chiba Mamoru again. At the cram school, a youma has taken over the teacher and steals the energy from the class. Ami escapes because she was listening to her MP3 player.
The youma chases Ami around and Usagi spots her. During the scuffle, Ami is knocked over a railing and Usagi jumps over after. As they hang, Ami changes her mind about become a senshi and changes to Sailor Mercury. Together, she and Moon defeat the youma.
Later Rei spies something wrong in her fire after Jadeite activates another Youma stone.