A romantic, innocent character, almost always a preteen or teenage girl, who is essentially a fairy-tale heroine in the present (or in the science-fiction future). She is naive, ignorant and insecure (especially about her body). She will be the target of every bully in the world, especially the Alpha Bitch. All she has going for her is her pure heart, which will save her — she never gives up, no matter what, and will eventually get the better of her tormentors.
But the Na´ve Everygirl is not a saint. She's particularly bad at showing gratitude, which tends to drive her friends away when she needs them. But eventually she will reconcile with the people who helped her, after wondering how she could be so blind.
This character is mostly a Discredited Trope on Western TV nowadays but were popular before 1990s; only the most idealistic shows on the Sliding Scale of Idealism Versus Cynicism (and occasionally their Deconstructions) have one nowadays. But in film and "young adult" fiction, she is inescapable. They are however very frequent protagonists of Shōjo (Demographic) stories written by women.
See also Wide-Eyed Idealist, Love Freak, The Ingenue. Compare Unlucky Everydude, her spear counterpart.
Miaka from the anime Fushigi Yuugi is an example with the dark side exaggerated, to the point where some fans thought it went too far.
Princess Nia Teppelin, main love interest in anime series Tengen Toppa Gurren Lagann, is the embodiment of an extremely idealistic fairy tale heroine trapped in a Super Robot show.
Sara Werec of Soukou No Strain fits this exactly, although her series slides more to the cynical side than most under this page.
Tohru Honda of Fruits Basket is definitely this, especially with how she enters and approaches the various members of the Sohma family.
Kana, Hatori's fiance, is arguably this, though one harsh Heroic BSOD snaps her to the point where she needs Hatori's Laser-Guided Amnesia to return to this persona.
Subverted with Shiina Tamai from Naru Taru. She does start out as one of these, but becomes progressively less innocent as the series progresses, culminating with her and her Shadow Archetype, Mamiko Kuri, slaughtering every human on Earth except themselves.
Seychelles, Liechtenstein and Taiwan have some traits as well, though they also have more energetic and strongwilled sides.
While C-ko Kotobuki is by no means a saint, she is innocent and optimistic, and she believes in love and friendship. Instead of bullies, she has weird shit happening to her at times. Though she doesn't seem to be too insecure about her body, she does have issues with being alone. She also has the "lovesick girl" aspect as well.
Oh poor, poor Jill and Princess Charlotte from Berserk. Two sweet and idealistic girls who live in a Crapsack World...
Abby in Coming Up Violet appears to be this on the surface, and indeed may indeed be a great example of this trope. However, she also harbors the heart of The Chessmaster.
Film — Animated
In The Princess and the Frog, we have Charlotte, being The Ditz and a complete romantic, wanting to fall in love with a prince and become a princess, a dream of hers since she was a little girl. In the end, she gives up that dream so that Prince Naveen and Tiana would get together and was generally happy for her best friend.
Bridget Jones is clumsy, insecure (especially about her body), and is very vulnerable yet won't give up her pursuit of love.
Jamie Bartlett from the Disney Channel movie Read It and Weep, who became so blinded by the prospect of being in the popular crowd that she pretty blew off everyone her inner circle and ignored her best friend Connor, who'd secretly been harboring a crush on her, only to lose this newfound popularity once it's revealed that her novel, "Is Saves The World", was truly a mockery of her high school and its cliques, which makes it difficult for her to gain back everyone's trust.
Essentially every single Disney Channel heroine can fit into this trope to some extent.
Most 19th century fairy tales have one, either male or female, and modern stories with a Na´ve Everygirl will often have a Shout Out to them. The main difference is that in the old fairy tales, she was just as likely to come to a bad end. (Hans Christian Andersen's "The Little Match Girl" is a particularly sadistic example, full of Glurge.)
Nita, the heroine of Diane Duane's Young Wizards series of books, started out a Na´ve Everygirl, but matured beyond that stage with the discovery and mastery of her wizardry.
Sci-fi author John Ringo tends to have subversions or inversions of this trope in his books. Megan Trevante and Mirta in the short story at the end of John Ringo's Emerald Sea, as well as from the later books of his Council Wars series are subversions of this, one being a very intelligent, tough and cunning young woman and the other spending most of her time pretending to exemplify this. The character Shenea, however, while being very sexual, exemplifies this trope. There are also several in his Paladin of Shadows series (mainly Katrina), which is odd considering the fact it is, by far, his most misogynistic series.
Nerdy little Clare, despite coming a long way, still falls into this trope even after the show's rebrand to Degrassi.
Title character of Ugly Betty, especially in earlier episodes. Though Betty has become less naive since then, she's still, of course, as idealistic as ever.
Laura Webber (later Baldwin, then Spencer) from General Hospital is an example of this trope, particularly during the character's original appearances from 1975 to 1982. When the character returned in 1993 she had become less naive, but still retained most of the other qualities of this trope.
Sophia Esteed of Star Ocean Till The End Of Time, although with less emphasis on a lack of gratitude (she doesn't have much to be grateful for, really) and more emphasis on her naivete and ignorance. Her body image issues are somewhat of a running joke through the game, too.
In the sequels of Disney's Cinderella, Anastasia, the redheaded stepsister gets retconned into a character like this.
Phoebe Terese on The Magic School Bus is a perfect example. She's the sweet natured, reserved romantic of the girls (once saying "Gee, what a guy!" about Arnold and found the notion of a bullfrog couple "romantic"), and tried saving the desert animals (which failed, due to the animals not needing to be saved, as pointed out by Carlos). She's also been picked on by Janet on different occasions, had the class turn on her once, and neglected to realize everything Ms. Frizzle did for her in "Goes to Seed". Despite her advocacy club failing, not being able to name three good things about recycling, and inability to do a slam dunk, Phoebe doesn't give up and retains her innocent nature.
Aaahh!!! Real Monsters: Gender aside, Ickis fits this. He's got all of the flaws, plus a tendency to say he's giving up... only to come back when it counts.
Sharon Spitz from Braceface fits this trope to a T.
Ginger from As Told by Ginger. Dodie and Macie also fit this trope. Even Courtney seems to fit this to a lesser extent (particularly in the high school years).