Tokiko Mima, nicknamed "Key," is a robot who has been raised as a human girl by her inventor/grandfather in a small, idyllic village in Japan. As her grandfather is dying, he tells her that she can become a human, provided she can make 30,000 friends before her battery runs out. With this, Key moves away from her idyllic village and heads for Tokyo.
Here she finds her best friend from Middle School, Sakura Kuriyagawa, working three different jobs to keep afloat. With her help as well as the help of Sakura's friend Shuichi Tataki (neither of which are convinced by Key's story), they plan to make Key into a Idol singer. They reason that someone following in the footsteps of Production Minos' biggest star, the mysterious Miho Utsuse, could easily gain the friendship of 30,000 people.
However, in times of extreme stress or danger, a second personality emerges from Key's emotionless form, revealing a girl that is not only more like a human, but one who appears to do supernatural feats.
Key the Metal Idol was released as a 15-episode OVA over a few years. The final episodes are nearly 90 minutes in length.
This show provides examples of:
- Anime Hair: Key has impressively spiky hair that would make Cloud Strife blink.
- Anyone Can Die: Both major and minor characters are offed during the series, especially in the finale.
- Applied Phlebotinum: Gel.
- Asshole Victim: Ajo dies in a really horrifying fashion. He's also an utter monster who absolutely deserves it.
- Awesome, but Impractical: Ajo's PPOR robots; yes, they're humanoid, super-strong, and self-powered, but there are still a lot of bugs to work out. Such as the way they only really work when they're controlled by the same people who contributed the "gel" that powers them.
- Miho's career is an extreme example. Because her career is basically a front for testing the PPOR technology, at least half of Ajo's skullduggery is so he can make his company's idol singer sit in a soul-draining control chair and control a malfunction-prone robot made in her image.
- Become a Real Boy: Key's goal, as a self-declared robot, is to become human.
- Bittersweet Ending: What can be made out of it, anyway. Key gets to become fully human, and she brings flowers to Miho who is recovering in a hospital... But that still doesn't change the fact that many characters, including Sakura, died because of Key, and "becoming human" also includes the emotional burden that comes with it.
- Bland-Name Product: Look closely in some scenes and you might see a Pony CD player...
- Broken Bird: Sakura. The lyrics of the ED theme, "I'll Be There For You", alludes to it, well before it's revealed in series.
- Childhood Friend Romance: Unlucky Sakura.
- Cloudcuckoolander: Deconstructed. Key's abnormal behavior is portrayed as unsettling and is not Played for Laughs.
- Con Man: Prince Snake-Eye.
- Cool Loser: Tataki.
- Corrupt Corporate Executive: Ajo.
- Crazy-Prepared: Wakagi seems to be ready for just about anything that could possibly threaten Key. As he should be.
- The Dragon: Sergei/D.
- Exotic Eye Designs: Key's eyes are a light shade of purple with tiny pupils and a dark purple-colored rim. To add to her strange and robotic appearance, they look like they're perpetually wide open with shock. As a human, they're brown and softer.
- Fanservice: Sakura and Key apparently need to shower often. And Hikaru makes sure all the bases are covered.
- Fetish: Ajo has a truly disgusting obsession with robots.
- Flipping the Bird: Miho in the opening sequence, if your pause-button finger is fast enough.
- Four Eyes, Zero Soul: Hikaru Tsurugi, the mercurial genius who originally mentored Miho and decides to take Key on as a special project.
- Freeze-Frame Bonus: The series constantly pelts the viewer with massive spoilers, but they're almost impossible to notice.
- Gainax Ending
- Generation Xerox: Sakura's father claims to have had an affair with Key's mother in the past. Sakura knows about it, it turns out, which explains why she started to act possessive towards Shuichi after he became more interested in Key's mysteries; she's afraid that they will relive their mothers' conflict, even though Key has shown romantic interest in nobody.
- Hollywood Hacking: Downplayed. Tsurugi is able to hack the electronic controls of his prison cell with the computer his captors graciously provided him, but it takes him at least four episodes/one In-Universe week of non-stop work.
- Human Resources: The "Gel" that powers the PPOR/"Sipe" robots is extracted from humans — usually unwillingly — and leaves the donors comatose and barely alive when too much is taken.
- I Believe That You Believe It: A frequent reaction to Key's claims of being a robot by those who know her.
- Idol Singer: Deconstructed. The weirdness surrounding Miho Utsuse's career strongly resembles the darker side of normal show business, with her being made into a manufactured product, drained of all life, and replaced by someone else considered to be indistinguishable from her.
- Improbable Weapon User: Tomoyo's preferred weapon is a wrist-mounted slingshot that fires explosive slugs.
- Inelegant Blubbering: Key's first response to becoming human and the emotions that come with it; understandable, considering that she basically hits the ground already past the Despair Event Horizon.
- Info Dump: Episode 14 spends the bulk of its 90 minutes on exposition for what's been going on the entire time.
- Kick the Dog: Ajo does this at least once per episode.
- Leaning on the Fourth Wall/Postmodernism: One manner to interpret this perspicacious exchange uttered by Wakagi and Shuichi in Episode 14 after Shuichi engages in disclosing what he has learned from his visit to Mamio Valley:Wakagi: There could be multiple universes, but Key should only have two futures... to regain her humanity, or fail. Any action should lead to one or the other. Her future should determine her present, and we should have been performing our given parts, but an element of uncertainty suddenly interrupted that determined plot. You! You still can't fit into your role. Do you realize how your good intentions have warped the future, thinking it was for Key's good?
Shuichi: How could I change the result? Would Key transform into something inhuman?
Wakagi: Exactly! Something inhuman, but we can't go back anymore, and I thought your role was the Greek Chorus.
- Mecha-Mooks: The PPOR combat robots.
- Mega-Corp: Ajo Heavy Industries, and their media subsidiary Production Minos.
- Messy Hair: Key obviously doesn't care much about her appearance.
- Mind Screw
- Mr. Fanservice: Hikaru Tsurugi, the resident bishonen who spends most of his screentime half-naked. His beauty is only skin deep, however.
- Model Scam: Happens to the very naive title character. Fortunately, the scumbags ordered delivery, and the delivery girl turns out to be Key's childhood friend Sakura, who figures out what's going on and saves her.
- Mysterious Protector: Wakagi, who has been appearing from the shadows when Key was in trouble since she and Sakura were in school together.
- Nightmare Fuel Station Attendant: Feeling up the Robot Girl version of Miho, cutting her artificial skin, while wearing a leather "robot" mask and calling her his "son" — Ajo qualifies with flying colors..
- No Social Skills: Key's conditions have left her with a distinct lack of people skills.
- OVA: Not only is the content of the show unusual for its time, but it was released as an "experimental title": while the fifteen episode amount is unusual enough, the first thirteen episodes run normally (25 minutes), while the last two are about 90 minutes apiece. Also, when it was first released in Japan, it was initially a far lower price than most OVA series (a VHS of the first episode was around 2,500 yen (appx. $20), and a 3-episode laser disc was 5,800 yen (appx. $55), which at the time was less than half of other OVA sets). By the time the final episodes came out, it was priced normally.
- Punch-Clock Villain: Staff A, B and C. We never learn their names, and they still end up dead in the end like almost everyone else.
- Red Baron: D. Yes, it's his code name, but A, B and C just don't sound as cool. And they aren't.
- Ridiculously Human Robots: Part of the Deconstructor Fleet. Key is introduced as a robot who's "very well-made," able to drink water, shower, and sleep, and this leads to everyone in school bullying her because they assume that her robotic behaviour is just for fun and that she's a human having delusions. Even her Only Friend, Sakura, wishes Key would just give up on "pretending." Then the accusation that she's just a human turns out to be true.
- Robot Girl: Key, of course, and the many Miho and Beniko robots running around. Subverted, since Key only thinks she is a robot, due to a failed experiment by her grandfather that sapped Key of much of her emotions and memory.
- Scam Religion: Prince Snake-Eye's "Church of the Golden Snake Savior". Although he ultimately means well, he begins trying to recruit Key in order to heal a sick child who'd gone too long without conventional treatment (because of his parents' faith in him). After Key heals the child, he enlists his remaining cultists to sabotage Sakura's attempts to get Key into show business so he can win her back.
- Shout-Out: Videos of Eraserhead and Twin Peaks: Fire Walk with Me appear in the video store scene in episode 2.
- Shower Scene: On a regular basis, as noted above.
- Smug Snake: Tamari.
- Stripperific: Beniko's stage outfit at her debut during Miho's concert late in the series.
- The Svengali: Tsurugi was Miho's mentor until she left and joined Production Minos (Ajo). It becomes clear that there were hurt feelings on both sides of the relationship when they meet again in the fourteenth episode. It also becomes clear that he's started to view Key as his Greatest Second Chance.
- Technopath: Sergei eventually realizes that he's gained the ability to control the PPOR robots without any devices, thanks to his frequent abuse of Gel.
- Third-Person Person: Key combines this with Spock Speak and Creepy Monotone. In the Japanese version, she switches between "atashi" and "Key," but in the dub, she always uses the third person. She still speaks in the third person after "becoming human", making the transition all the more disheartening.
- Tsundere: Sakura, particularly when talking to Key.
- Unrobotic Reveal: Key is actually a human, but her emotions were removed during a failed experiment done by her grandfather, hence why we're (and she's) led to believe she's a robot.
- Villainous Breakdown: Ajo, several times.
- White Hair, Black Heart: Sergei.
- Would Hit a Girl/No-Holds-Barred Beatdown: Beniko casually makes an offhand remark that prompts Ajo to punch her out of her seat. When she calls him out on it, he proceeds to beat her 'til she's bruised and bloodied, while pointedly telling her how little he regards her gender, her looks, her singing voice, or the fact that she's an idol.