A character needs to undergo a complete physical sex change, usually through magic or Applied Phlebotinum, in order for them to access their powers. Typically, this motivates them to choose a sex transformation they wouldn't otherwise want. With many examples, the character changes back to their original sex when their powers are dormant, especially if they're a Henshin Hero. Others have powers that are always "on", which leaves them transformed persistently, often permanently.
This trope gives a new twist to the classic secret identity, as the character not only has to face the responsibility of having great power but also the hardships of living as a new gender.
Might be used to deliver An Aesop about how being yourself is greatly empowering.
- BoBoiBoy: Played with. In episode 5, Probe's Super Mode gets activated while the robot is Disguised in Drag. He turns into "Super Mrs. Probe", changing from purple to a pink, lady-themed battle robot. He doesn't seem intimidating at first, but he can launch a Macross Missile Massacre from his handbag, shoot kitchen knives, and wield a giant spiked rolling pin, among others.
Adu Du: Hey, what's wrong with you?!Super Mrs. Probe: Um, sorry. Mommy's still stuck in character!
- Zig-zagged in Ayakashi Triangle: Matsuri's male-to-female transformation itself has no notable effect on his existing combat abilities—Reo's analysis showed a small Discard and Draw effect, but not one that was ever plot-relevant. However, because Matsuri's powers are spiritual in nature, his mother finds a way to use his female identity as a bizarre form of mental training. Matsuri dislikes being a girl, so doing feminine things causes him mental stress, and overcoming that makes him more powerful. Just by changing from fundoshi to girls' underwear and getting used to it, Matsuri is able to handily defeat an enemy as strong as a previous one that completely overwhelmed him.
Matsuri: I'm not a girl just for show!
- An instance occurs in Bakugan, which features Masquerade, who is really a gender-bent form of Alice. It's an odd case, however, because it's also a case of a Jekyll & Hyde scenario - Alice is completely unaware of any actions she commits as Masquerade, and the two interact in Alice's psyche numerous times, proving they have separate consciousnesses. Eventually, the two commune with one another, and Masquerade fades away into Alice's psyche, while the latter retains access to the former's Bakugan partner Alpha Hydranoid and abilities.
- In Fushigi Yuugi: Genbu Kaiden, Rimudo has the ability to switch between male and female forms. He usually stays male, but his Celestial Guardian abilities are only available when he's in his female form.
- In Kämpfer, Natsuru Senou was chosen to become a Kämpfer. Thanks to this, Natsuru gains great strength and fighting abilities. On the other hand, it's apparently a rule that Kämpfers can only be girls, so any boys that are chosen transform into girls when their powers activate.
- Oto × Maho is a story about a boy named Kanata that becomes bound by a Magically-Binding Contract to become a Magical Girl. It's a bit of a subversion since despite getting the outfit, he remains physically male, though he looks so feminine and has such long hair that it's hard to notice. The only case where he'd end up turning into a girl for real is as punishment for breaking contract, i.e. when he stops being a Magical Girl.
- Sailor Moon:
- The Sailor Starlights are a subversion and inversion in the 90s anime. They're male most of the time and transform into females to use their Sailor Guardian powers, but it's eventually shown the latter were their original forms—their princess is surprised to see they've chosen male civilian forms. In the manga they were female the whole time, merely dressing as boys while in their civilian identities.
- The French dub tries to cover up Sailor Uranus loving another woman by changing the character from an androgynous woman to an androgynous man who turns female to become a Sailor Guardian.
- Guardians of Order's Sailor Moon tabletop RPG (released in 1998) establishes this as a trait of male Sailor Guardians, with one author playing Yuuichirou as "Sailor Nebula". Why? The writers got their wires crossed regarding the Starlights, believing them to be guys whose female forms are an aspect of their Sailor Guardian powers.
- Pretty Cure
- Subverted with Itsuki Myoudouin from HeartCatch Pretty Cure!: She looks and dresses like a (pretty) boy and has a Cure form just as girly as the others. However, Itsuki not only fully identifies as female, she's actually much more feminine than she presents herself, but thinks a masculine front is needed to show strength as the Heir to the Dojo. Working as a Cure made her realize otherwise. Considering that her designated nemesis is an Ambiguously Gay guy with a penchant for fashion, this might be a stealth queer aesop.
- Although Phantom from HappinessCharge Pretty Cure! already has powers, he spent one fight transformed into an (also female) Evil Knockoff of Cure Lovely.
- Inverted in PHD: Phantasy Degree, where the set of Ring of Power MacGuffin allows the user to switch their gender, but decreases their power greatly.
- An interesting variant in Birdy the Mighty, where the protagonist doesn't really turn into a female superheroic version of himself, but is instead forced to be fused with a female Human Alien superheroine after she accidentally destroyed his original body. As a result, the two actually are separate characters, but share the same body and can switch between their respective appearance according to the situation.
- Mahou Shounen Majorian is about two boys given Magical Girl powers by aliens. Their sexualities become pretty confused in short order. Especially since one of them thinks Girls Have Cooties in response to being the only boy in a household of bossy older sisters.
- Magical Girl Ore Gender Flips the usual trend by making the heroine turn into a very toned man to activate her powers. It's eventually revealed that other girls have made that same gender-bending contract, and her crush falls in love with him during a Rescue Romance.
- Souji Mitsuka from Gonna Be the Twin-Tail!! doesn't just change genders whenever he becomes Tail Red, he actually goes from a teenager to a prepubescent child, thus inverting the Older Alter Ego trope.
- Ore to hero to Mahou Shoujo is about a man whose Transformation Trinket was supposed to turn him into a Henshin Hero, but ended up turning him into a pint-sized Magical Girl Warrior due to a mixup with a wand trinket. Later chapters show that the other trinket is in active use by a musclebound man in armor, causing the main cast to shudder at the thought of a little girl being his alter ego. It was another man; the girl who needed the original trinket shows up separately as an opposing force.
- Magical Trans is about a Club Stub whose president invented a phone app that transforms people into Magical Girls, even boys like Minami. In a twist, the transformation gives Minami massively boosted physical abilities, but there is No Antagonist to use them against (until Kaiserk shows up, and even she treats their "fights" as more of a hobby). He uses the app because he likes turning into a cute girl, and even gets an option to turn off the superpowers so he doesn't use them by accident.
- Magical Girl Kakeru is about a boy in middle school who accidentally gets Magical Girl Warrior powers meant for his younger sister, which turn him female while in use, and becomes the youngest member of a magical girl team. In a twist, these abilities are powered by femininity, initially making Kakeru barely any stronger than when he was male. To be able help out, he has to spend long stretches of time still in female form, dressing and acting like a girl under his teammates' tutelage.
- Life with an Ordinary Guy who Reincarnated into a Total Fantasy Knockout: When Tachibana becomes a woman, his new form takes Attractive Bent-Gender to the point of being a literal superpower, able to elicit marriage proposals from men just by standing there and, at one point, causing an entire gang of bandits to take themselves out due to fighting over him.
- From Philippine comics, Zsazsa Zaturnnah is an effeminate homosexual and the proprietor of a small town beauty salon. He has a huge spiky stone that physically transforms him into a superhuman woman whenever he ingests it and shouts the word "Zaturnnah!". His female form is similar in both powers and appearance to Wonder Woman (as well as to Darna, another notable Filipina superheroine, whose stone-swallowing transformation was parodied by Zsazsa's character).
- Mantra from The Ultraverse. Originally a male warrior, he gained magical powers after his soul was transferred into the body of a woman.
- In The Savage Dragon, the power to turn into Mighty Man, a Captain Marvel Expy, passed on to Ann Stevens, a nurse who becomes a tall, blond, male superhero when she taps her wrists together (a transformation method that's a nod to another Captain Marvel).
- In Alan Moore's Promethea, one of the former Prometheas was a male comic book artist called Bill Woolcott.
- The HERO Dial in Dial H for Hero will, very rarely, turn a man into a female hero or a woman into a male hero; in the case of "Shocking Suzi", formerly Joe, he lost the dial before he could turn back and remained a superpowered woman for the rest of his life. Though he was also slowly losing his powers, meaning he'd eventually be just a regular woman.
- Great Lakes Avengers: Goodness Silva, AKA "Good Boy", is a teenage girl whose super-power is the ability to turn into her "fursona", a hulking blue male werewolf.
- Back in the late 70s/early 80s, Captain America would occasionally fight a villainess named the Vamp, whose power was transforming into a telekinetic, distinctly male caveman with a giant head. This form was named Animus, in a nod to Carl Jung's theory that women have an unconscious masculine side named the animus.
- Cybersix inverts this trope, with the titular Artificial Human being female, but crossdressing for her secret identity.
- Living your best life is a Miraculous Ladybug fic where due to seeing Magical Girls as his ideal heroes, Adrien can use the Black Cat Miraculous to become the magical girl Chat Noire.
- In the book Geeks Girls And Secret Identities, the protagonist discovers that his town's superhero, Captain Stupendous, recently died and passed his powers onto his crush, Polly, who now transforms into Supendous' male superhero form. Eventually the aliens who gave Stupendous his powers show up and give Polly a new, female form.
- In Magical Girl Raising Project, not all magical girls are female in civilian form. La Pucelle is actually a young boy named Souta Kishibe. He's secretly a magical girl fanboy and jumped at the chance to become a real magical girl. He turns into an teenage girl when he becomes La Pucelle.
- The protagonist of Princess Holy Aura starts off as a man in his mid-30s, who - owing to the nature of the powers - needs to turn into a 15-year-old girl to utilize them. In order to maintain The Masquerade, he starts needing to use that form in everyday life, too.
- Whateley Universe: It's a central premise — in the The 'Verse, mutants have about a 1 in 3 to 1 in 6 chance of being Exemplars, and thus having what's called a BIT — Body Image Template. Long story short, in Generation 1, these mutants have an idealized shape they associate with themselves, which can be just about anything — including the "wrong" gender. The majority of the stories revolve around a clique of students who had a Gender Bender during their origin stories, and are part of Poe Cottage — a dorm designed to hide this fact (as well as other LGBI students) from the study body at large.
- Nemesis Series plays with this trope, Danny Tozer is a very closeted trans girl who is still presenting as male to most of the world. However, she happens to be present when the world's greatest superhero Dreadnought dies, his last action to pass his powers on to her - one of the side effects of this power is for it to turn you into your idealised version of yourself which shifts Danny's body to match her gender identity (previous holders of the mantle of Dreadnought had all been cis guys who just got taller or regrew lost digits). Unfortunately her parents are massively transphobic and do not react well to this revelation.
- In the New World of Darkness fan game Princess: The Hopeful, it's possible for a player character's to have been male before their transformation. However, this is not necessarily a source of embarrassment, since the transformed state is an idealized version of the person in question, so any Princess who gender bends when transforming is probably transgender in the first place. However, they can't just stay transformed permanently because most Nobles don't have that as an option (and the ones that do use the magic that drives them insane).
- Espgaluda series: The heroes are already powerful psychics, but gender-changing makes them into even more powerful psychics.
- Milton from Fable III is male; however, if the hero is female, Milton will swap genders when he assumes the hero's form, as well as gaining the power of a Hero.
- In a disturbing variation, beauty-obsessed Bishōnen Morpheus from Resident Evil: Dead-Aim seemingly changes gender when he mutates into an incredibly powerful Tyrant-esque mutant, with an obviously feminine voice, face and figure. The virus that mutated him is even called the T+G-Virus. He gains super strength, speed, agility and electricity powers, but that electricity is produced by two organs on his chest that look like breasts. There is absolutely no reason for him to gain organic Combat Stilettos though. Considering what previous TG-Virus test subjects turned out like, Morpheus got off lucky with his new good looks and powers until he sustains too much damage and his Healing Factor goes out of control...
- Max's Big Bust: A Captain Nekorai Tale has its titular character Max changed from a man into a particularly buxom woman near the beginning of the story, and later on it's discovered s/he has electrical powers as well. Two other characters (Amber and Holly) get given their own elemental powers later on when they also get turned into similarly buxom women, but they do not count for this trope as both were already female.
- Elliot from El Goonish Shive acquires a spell that allows him to turn into a voluptuous superheroine. Note that he is already pretty powerful due to his Supernatural Martial Arts and occasional cases of this trope. He also isn't too bothered by the gender-changing aspect: hanging out with Tedd has made him used to that sort of thing, and besides, superpowers!
- It does somewhat bother him, which ends up being pointed out when he notices every subsequent spell he gets seems to involve making him female for some reason. Tedd theorizes the original "become a superheroine" spell was influenced by external factors to specify "female", that he's not really fine with this, and that all of his subsequent spells are on some level attempts to correct the initial mistake...but get stuck on the "turn female" part and thus doomed to failure because changing gender still bothers him. However, much later on he starts changing his tune to the extent that his sister/duplicate, Ellen, questions whether he even has a gender identity in the first place.
- Discussed and deconstructed with Magus, who comes from another dimension where magic is common. Men are associated with having more powerful magic since they are physically stronger, and thus many biological females including Magus who want to pursue battle magic change their default sex through magic. Terra (the alternate universe version of Tedd) is the exception to this rule, and she and Ashley have questioned Magus on whether it's truly the male form that gives someone more powerful magic or if that's just a gender stereotype. However, Magus himself seems to truly identify as a man, such that even in spirit form he is clearly masculine.
- Sparkling Generation Valkyrie Yuuki. The protagonist is an average male Ordinary High-School Student chosen to become a Valkyrie. However due to the fact that all Valkyries are female, he got transformed into a female to access those powers. He gets two new identities: one as a female version of his other self, and the other as an idealized Magical Girl version of that new self.
- Exposure to Virus-X gave the T-Girls of the Remix Comic version of Jet Dream low-level super powers (enhanced agility, strength, and endurance). Their exposure was accidental, but a voluntary procedure for recruiting new T-Girls is also described.
- In Jill Trent, She-Sir Science Sleuth, when Femavium interacts with the spinal fluid of a man, the result is a transformed woman with super powers that seem to vary according to the recipient. Jill gains "girl-brain cells with the proportional density of 58 girls." Another character gains "the flexibility of 45 ballerinas."
- Thanks to a Secret Legacy from his Japanese immigrant mother Magical Girl Neil starts transforming from an Ordinary High-School Student to an Oni-fighting Magical Girl Warrior on his 16th birthday. He is, needless to say, not particularly thrilled by this. Underscoring his unconventional nature, his primary ability consists of the ability to summon a variety of household appliances which he uses as bludgeons or projectiles as the situation requires.
- Played with in Magical Boy: Max's Magical Girl transformation does not make him change sex because he's a transgender boy who has not transitioned medically. However, it does put him in a hyper-feminine outfit, and even destroy his chest binder. As Max is very anxious about his gender, partly because his mother is very unsupportive, this flat-out traumatizes him at first. As he gets better control of his power, he manages to make his transformed outfit more masculine.
- Downplayed on Steven Universe: Amethyst fights in wrestling matches as "the Purple Puma", using her Voluntary Shapeshifting to become a larger, beefy man. For the most part this is just a Paper-Thin Disguise so her teammate wouldn't learn about her career. Amethyt has mostly the same powers in any form, but at least once Amethyst turned into the Purple Puma for an actual fight (it's also an attack in Attack the Light). The fact that she switches gender is pretty much incidentalnote , and given how Crystal Gem biology and culture works, she didn't really have a gender or biological sex to flip in the way humans understand the term.
- Like the comic it's based on, Cybersix inverts this; the title character's secret identity is the one she crossdresses for.