"The Mugen Academy is hosting the next National Practice Exam! Of course, Ami's attending since studying is her passion. I really wish it were mine too. Anyway, try not to jinx her by using words like 'failing', 'dropping out', or 'falling behind' around her, okay? Because if you do, then In the Name of the Moon, I'll punish you!”
— Usagi Tsukino
(CWi Episode: "The Science Of Love")
Thanks to Ami having an upcoming practice exam at Mugen Academy, the girls are given another opportunity to investigate the school. Though their efforts are halted by the penultimate Witch, Viluy, who targets the test takers for their Pure Hearts. As this happens, Haruka and Michiru gain an opportunity to attack Hotaru.
Tropes in this episode include:
- Arson Murder And Life Saving: In the last scene, Haruka criticizes Ami for letting her kind heart allow Hotaru to escape. But then she expresses gratitude for being saved thanks to her kind heart.
- Badass in Distress: Mercury, Uranus and Neptune end up in the mercy of Viluy's nanobots and are only able to fight back when Moon and friends show up to distract her.
- Barely-Changed Dub Name: In the Cloverway dub, Yui Bidou becomes “Julie Bidou”.
- Bathos: Ominous music plays as Professor Tomoe and Kaolinite look at the large turn out of unfortunate souls who've come to take the practice exam. He then notices Usagi in line eating snacks while Kaolinite brushes her off as an outlier.
- Big "SHUT UP!": Viluy says this to Kaolinite who insists on handling the Sailor Guardians instead of her.
- Bittersweet Ending: Hotaru disappears before the Guardians can reach her while Tomoe discovers most of their identities. But at least there's a moment of peace between the Inners and Outers thanks to Ami's kindness.
- Continuity Nod: The girls start the episode by discussing Tellu being a student at Mugen Academy.
- Crazy-Prepared: Ami sheepishly admits that she's been studying for the past six weeks for a practice exam being held at Mugen Academy. This works perfectly for her friends who want to use that as an opportunity to sneak in the school again.
- Death by Secret Identity: Viluy uncovers the true identities of Mercury and the Outers but she's killed in their one fight. Subverted with Professor Tomoe who learned of their identities via Sinister Surveillance.
- The Faceless: All of the exam attendees are covered in gray shadows and have very minimal features.
- For Science!: Ami argues that pursuing scientific endeavors with cold-hearted intentions is not correct and that science should be pursued for the benefit of humanity.
- The Gloves Come Off: Fed up with Viluy's cruelty, Sailor Moon achieves her Super form without anyone telling her and claims that she's done playing around.
- Grey Goo: Viluy's Mosaic Buster involves sending her nanobots to break apart a target of interest on a molecular basis.
- Gut Feeling: Michiru tells her partner that she has a bad feeling while inside Mugen Academy. Haruka picks up on it and asserts that she can feel dark energy coming from within the school.
- Hoist by Her Own Petard: Viluey's nanobots begin to destroy her body after taking a direct hit from Rainbow Moon Heartache.
- Ironic Echo: During Viluy's molecular breakdown, Mercury laments that her nanobots won't listen because they're scientific machines with no need for feelings, just like the witch boasted earlier.
- It Has Only Just Begun: The disembodied voice of Professor Tomoe boasts this to the Sailor Guardians as he escorts Hotaru away from them.
- Let's Split Up, Gang!: After Yui drags Ami to who knows where, Minako suggests that the rest of them split up into teams of two to look for clues.
- Mythology Gag: Yui infodumps on Ami about the five main subjects that Mugen Academy teaches and how students with high rankings are able to become instructors of those subjects. This is in reference to the manga where the Witches 5 were the heads of those educational subjects.
- Nanomachines: Viluy has created nanobots capable of serving her every command. From operating the Pure Heart stealing sequence to attacking her enemies.
- No Body Left Behind: Viluy's body vanishes into nothing after being broken apart by her nanobots. All that remains is her control bracelet which soon crumbles afterwards.
- No Sympathy: After Usagi admits to feeling like a lazy bum while comparing herself to the studying attendees, Rei chews her out by saying that she should have made more of an effort to study if she genuinely feels that way.
- Oh, Crap!: Usagi and Minako react this way after seeing the test takers have their Pure Hearts stolen through their computers.
- Passive Aggressive Combat: Viluy isn't afraid to throw shade at Kaolinite by asserting that she knows where her priorities are and how she isn't wasting her time flirting.
- The Rival: Yui Bidou aka Viluy has been taking practice exams and has gotten high scores that rival resident genius Ami.
- Secret Identity: Viluy admits that she's on a hunch about Ami Mizuno, along with Haruka and Michiru, being Sailor Guardians in disguise. She's proven right when they transform in front of her.
- Shadow Archetype: Viluy serves as a dark reflection of Ami regarding how they treat grades and human emotions. Unlike Ami who believes that there's more to life then getting good grades and that human emotions should be taken into consideration, Viluy believes that excelling at academics is all that matters along with not caring for the emotional needs of others.
- Sinister Surveillance: During the practice exam, Professor Tomoe is shown monitoring the event. He even spies on Ami believing that there's something off about her.
- The Slacker: True to her lackadaisy nature, Usagi informs Yui that she excels best at stuffing her face with snacks and going to dreamland.
- Sympathy for the Devil: Mercury openly laments Viluy's cruel fate.Sailor Mercury: Is this her punishment for believing that science is just logic with no love? Poor thing.
- Yank the Dog's Chain: The Sailor Guardians reach the throne room and find Hotaru. But before they can save her, or kill her in the Outers' case, she's transported away via dimensional rift by Professor Tomoe.
- You Have GOT to Be Kidding Me!: Rei, Minako and Mako have this reaction after Usagi proudly admits that her best subjects are napping and eating. Rei in particular hangs her head in shame after that.
