Is The Girl Genius a Monster: The Brainwashing Cram School of Horror

Usagi strikes up a friendship with Ami Mizuno, reputed to be the sharpest mind at her school with an IQ topping three hundred. Luna, however, picks up an odd energy signature around the girl and begins to wonder whether Ami might actually be an agent of the enemy rather than a potential ally.

Inside the Dark Kingdom, Jadeite briefs Queen Beryl on his study of Japan's schooling system. Meanwhile Usagi dreads her latest exam scores, and Luna grows exasperated at how little effort her charge puts toward locating the princess. That night Luna slips into the Game Center Crown, using the Sailor V machine to report to a hidden contact that no leads on the princess have surfaced and that Sailor Moon is proving unreliable. She also flags the peculiar aura she has sensed around a classmate of Usagi's.

When mock exam rankings are posted, Ami tops not only her school but the entire nation, drawing envy and gossip from Naru, Umino and Kuri, who assume she must be conceited. Usagi withholds judgment, and after class she befriends Ami despite Luna's objections, bringing her to the arcade where Ami sets a record on the Sailor V game on her very first try. Ami hurries off to her cram school, dropping a floppy disc that Motoki asks Usagi to return.

The disc turns out to be a brainwashing program built by the Dark Kingdom and distributed by the Crystal Seminar under the pretense of raising intelligence. Using her Disguise Pen to pose as a doctor, Usagi infiltrates the seminar and warns the students away from the machines. Ami's instructor is exposed as the youma Garoben, who seizes Ami and attacks. When the program fails to affect Ami, a Sailor Guardian symbol lights on her brow; Luna tosses her a Transformation Pen, and Ami becomes Sailor Mercury. Her debut Shabon Spray fogs the room, letting Sailor Moon finish the monster with Moon Tiara Action.

Junichi Satou directed the episode from a script by Sukehiro Tomita, and it first aired in Japan on May 2, 1992. The story adapts the second manga act, though with changes: in the anime Luna wrongly suspects Ami of spying for the enemy, whereas the manga has her sense a friend, and Ami's transformation item is delivered mid-battle rather than won from the arcade machine. It marks the first appearances of Ami, her Transformation Pen, the Mercury Power, Make Up phrase and Shabon Spray. In the DiC dub she becomes a transfer student from Brighton Academy, and Viz's version famously has Umino peg her IQ at over 9000, a line voice actor Ben Diskin recorded as a joke that made the final cut.