Describes himself as Mazinger's little sister, then reveals his gender by exposing his flat chest. Speaks with a girlish voice.

Haruhi's beautiful father. He crossdresses as female, but there are a few occasions where he shows his masculine side.

Fashionista extraordinaire. Finds girls' fashion more his style, even if his family disagrees

Got his fame as an idol for his girlish style. Is less than happy about it, honestly

Confusing the main character with your gender, and having a female voice actor earns you a spot on this list

Ritsu dresses as a woman because he feels he isn't strong like the males in his family. He's very agile though

Felix is best girl.

One of the oldest of the brothers, Hikaru prefers a more feminine look. As a novelist, he has the leisure of dressing how he wants

Sitri likes cute things, sweets, and being admired for being pretty. Is it no wonder this demon gets mistaken for a girl?

Forced into crossdressing by the student council as payment for repaying his parents' debt. One of many crossdressers in this series

His portrayal as a female was further confusing because of the American dubbing company taking away his identity as a male.

The main character's little brother and part of the disciplinary committee. Constantly has to report himself for wearing tge wrong uniform.

Head of the disciplinary commiittee and hates the student council. Loves dressing as a girl, though.

Dresses as a girl for the sake of Mitsunaga. Wears faily convincing false breasts.

It was only when this AI felt 'down under' and gasped 'it's gone' that his gender was revealed.

Hajime's little brother, extremely sturdy, and a total personality opposite of his brother.

He is feminine enough to be mistaken for his twin sister. He gets a girls' bathing suit. Even his classmates don't believe he's a boy. His gender is Hideyoshi, neither male nor female. 

I'm with the other swords on this one. I'm still not sure the tantou is a boy.

Just when everyone tgought, 'Finally a female presense' in this sausage-fest of a show, she turns out to be a he... In transition.

Do jellyfish really have gender?

By Night, La Pucelle, Dragon Knight and female. By day, Souta, regular middle school boy.

When the manga introduces Husky, he's a mermaid princess in a traveling show. His girlish looks are pretty convincing.

Akito's cute-side is extremely feminine and bubbly, confusing just about everyone.

Looks like a woman, acts like a mega bitch, god that deep voice is off-throwing.

The fact that the other leads both mistook Nasu for a girl is the very reason he is on the list.

Count D is a man... no matter that he's got a prettier, more feminine face than any other woman in the manga.

The entire plot of his anime is that 'dude looks like a lady' and confuses the love interest.

Was apparently originally designed to be a woman, then the mangaka decided against having Inuyasha beat up human women... but didn't change the character design

Yes, he looks feminine. Yes, he likes sewing. No, he is not a girl.

Really didn't help that the English dub voices him as a female to ward off homophobic commentary. At least they did him right in the remake

Ok, so this one is really confusing. He's genetically engineered and unstable, so he sort of transitions between genders... randomly.

If often mistaken for a girl. Draws doujins ofhimself and his brother.

Mare was created to have girlish features and wears girlish clothes, while his twin sister is the tom boy.

Tetra was male in the real world, but because he had a female avatar, is female after the Apocalypse. His/Her gender confuses the guild of Log Horizon. I don't even know what gender Tetra seems themselves as, if they even try to define it. 

Literally, the title of the anime is that Ryou is a beast in a skirt.

His name is Julia, he's prettier than most girls, and he's a priest in Africa when we first meet him.

V.V. may look like a pretty little princess, but he's actually super old... And a he. It really doesn't help that he has a female VA in English.

Not only do his only classmates confuse him for a girl, but night club partiers as well. And with those little fluffy pigtails, the slender build, and female voice actor? It's not hard to see why everyone gets Nagisa's gender confused...

Aoi has made a name for himself as an internet idol and loves cute things. This includes making himself into the cutest girl possible.

Asuramaru may look feminine, may have Colleen Clickenbeard as his US voice actor, but this demon sword is definitely a dude.

With his flowing blonde locks, on point eyeliner, and flamboyant costume design, he may be mistaken for a female by some.

This apprentice seeker wears a frilly maid's outfit as part of his job in the seeker camp. He's also voice by Aki Toyosaki, so it's ok if you got confused on his gender.

This middle school student has employed a rather adorable crossdressing scheme to confuse his gaming opponents.

I can't be the only one who first saw Tokitou's youthful cloud watching and thought 'what a lovely girl' only to find he was in fact a genius boy.

Iwao is a member of the eccentric beading club, and he dresses like a girl.

Maybe its the perpetual smock wearing, maybe it's the hair ribbons, or maybe its his youthful face but Suou tends to look very feminine.

When this member of the Ten Commandments first shows up, the long hair and convenient body covering of vines was really not meshing with his voice. And then, revealed he's definitely a guy.

I can't be the only one who saw this sadistic cherub with his rapunzel hair and was confused about his gender.

I'm not sure if it's that Hikaru looks like his sister Hinako or that his sister looks like him, but they're able to swap places with just a wig.

In an anime about girls flashing their undies at a kowtowing bodyless voice, Tama surprises the MC by being... a boy.