"Do you have any interesting hobbies?"
"Some people say it's eating, but I think it's sleeping."
-Julie Bardot and Serena
Amy meets Julie, whom she gets into an argument with when she learns of Mugen School's methods of the smarter students leading the classes. Julie is actually Byruit, who pushes Kaorinite to the floor after bashing her for not doing any work. Byruit is wearing a nanocuff, a bracelet that controls all her machines, including nanomachines. She activates her master computer, connected to the other computers, which extract the Pure Hearts of all the exam takers.
Amara and Michelle sneak into the basement of Mugen School, which is Doctor Tomoe's main lab, and his base of operations. They find Hotaru possessed by the Sovereign of Silence. Amy tells them that Hotaru is being used by the Heart Snatchers, but they don't believe her. Byruit appears and attacks Amara and Michelle with an energy beam from her nanocuff, containing nanomachines that slowly begin to dissolve them.
Amy transforms into Sailor Mercury and uses Shine Aqua Illusion to freeze the nanomachines, but they break free of the ice and attack her. The other Sailor Scouts arrive. Amara and Michelle transform into Sailor Uranus and Sailor Neptune and attack Byruit with World Shaking and Deep Submerge. Sailor Moon uses the Purity Chalice to transform into Super Sailor Moon and uses Rainbow Moon Heart Ache on Byruit, damaging her nanocuff and causing it to backfire on her. The nanomachines in the beam slowly begin dissolving her. Her master computer is destroyed and all the Pure Hearts are returned to their owners as Byruit is completely dissolved, leaving only the nanocuff. As it dissolves into dust, Sailor Mercury says that it was her use of science without love that resulted in her death.
The Sovereign of Silence says the battle is just beginning, and leaves.
- First unshadowed appearance of Byruit
- Final appearance of Byruit