Act 2 Ami - Sailor Mercury

Luna begins to suspect that one of Usagi's classmates, the top student Ami Mizuno, could be a fellow guardian and ally. At the same time, Jadeite of the Dark Kingdom's Shitennou exploits a cram school to drain energy from students and enslave them. Naoko Takeuchi wrote and illustrated the chapter, the second of the Dark Kingdom arc.

In a shadowy realm, a long-haired woman scolds a blond man for failing to recover the Silver Crystal. He apologizes and, named as Jadeite, the Dark Kingdom's Far East Commander, swears to Queen Beryl that he will find it, since their great ruler hungers for energy. At home, Usagi defends Luna after her mother, Ikuko, teases the cat and earns a scratch. Luna reminds Usagi that she has only just become Sailor Moon and that the enemy will return, urging her to seek out her fellow guardians and guard the princess. That night Luna works a computer at the Game Center Crown and turns up a file on a girl named Ami Mizuno.

At Juban Public Middle School, classmates marvel at Ami's record-topping entrance exam and gossip that she is cold, friendless, and endlessly studious, crediting her success to the pricey Crystal Seminar. Walking home with poor grades in hand, Usagi crosses paths with Ami when Luna leaps onto the girl. The two strike up a friendship, partly because Usagi hopes some of Ami's brains will rub off on her, and head to the arcade. At the Game Center Crown, Ami plays the Sailor V game to a crowd's amazement, scoring high enough that a pen drops from the machine, and a jealous Usagi bangs the cabinet until a different pen falls out. Ami then hurries off to the Crystal Seminar, which she attends daily in hopes of becoming a doctor like her mother.

Later, Usagi finds Ami taking handwritten notes because the seminar's discs fog her mind, and invites her for ice cream, but Ami leaves for the seminar and forgets her disc. On the way to return it, Usagi and Luna receive a flyer picturing Ami and promising genius through crystal discs, while the blond man Usagi keeps bumping into grows suspicious after hearing Luna speak. Playing the disc, Luna and Usagi hear a hidden message ordering listeners to serve the Dark Kingdom and hunt the Silver Crystal. Spotting a brainwashed Ami among the seminar crowd, Usagi uses her arcade pen and the cry of "Moon Power" to disguise herself as a doctor and shake Ami free of the spell.

Inside the classroom, the instructor, secretly a Youma, hurls stinging papers at a transformed Sailor Moon. Her tears set off the odango covers and shatter the windows. Tuxedo Mask lifts her clear, tells her to protect her friend, and vanishes. Sailor Moon defeats the Youma, and Ami is revealed as Sailor Mercury, guardian of water and wisdom, giving Usagi both an ally and a new friend.

Debuts include Ami Mizuno / Sailor Mercury, Queen Beryl, the named Jadeite, and the unnamed Garoben Youma, along with the Crystal Seminar setting, the Disguise Pen and Transformation Pen, and the Sailor Moon Kick. A running gag turns on Usagi mishearing the word for "princess" (purinsesu) as "pudding" (purin); localizations vary the joke, with Bunny craving Pringles in the Mixx release, wanting royal chocolate in Kodansha's edition, and going for princess cake in the Eternal Edition. The Crystal Seminar's discs first appeared as floppy disks in early versions and the first anime, then were redrawn as CDs from the Shinsouban printing onward.