Here's just a fun article about some anime characters based on their zodiac sign. I tried to follow the canon as best as I could, which meant I couldn't use any character more than a 100 years old.
Also, this list is mostly Death Note characters so take it or leave it. And I didn't use Sailor Moon at all because that would be too obvious.
Aries: Eren Yaeger (Attack on Titan)
Yes of course Eren is an Aries. He's really annoying, screams a lot, and thinks that he's going to save the world even if he's never accomplished anything on his own in his life.
The thing about Eren is that, as the main character, he's always blaming himself for things that are literally too big for him to handle. He's not the strongest character or the bravest one, but he's singleminded about what he wants and will do anything to get it, except tell a lie. He's always unstrategically direct and honest.
For most of the series, Eren acts instinctively. He's not a planner and he doesn't test things out. He does well in an army where most of their plans go to shit because he's always ready to do what is needed all the time.
Taurus: Tohru Honda (Fruits Basket)
Tohru is living in a tent in the Sohma household's backyard when they discover her and invite her to live with them until her grandpa is done renovating his place. Then, she ends up staying forever.
Taurus is known for its staying power. Let a Taurus crash at your place for the night and you might just find that they're already changed their mailing address. A year later, they've married their way into your family.
How does Tohru get to stay with the Sohmas until she's well overage and legally part of the family? Well, it's by doing all the nurturing work, like cooking and cleaning and taking care of people every single fucking day. Whatever a Taurus gets in life, my god they've definitely earned it.
Gemini: Shinji Ikari (Neon Genesis Evangelion)
Shinji is a kid who just can't make up his mind. Should he pilot a giant robot and save the world? or should he just take the train off somewhere and stay there until the apocalypse? His decision will not surprise you because it changes every single episode.
SPOILER: At the end, we find out that there's at least the possibility that everything we've seen so far actually happened in Shinji's head. With the singularity upon us, everyone we've met so far can just be a figment of Shinji's imagination. This is very Gemini because only a Gemini might entertain the idea that everyone they've ever known has been completely delusional.
If you want to know what it is like inside a Gemini's head, just watch the last two episodes of Evangelion.
Cancer: America (Hetalia: Axis Powers)
Throughout the show, America is constantly eating junk food and drinking soft drinks. According to the mangaka, he's inherited England's lack of taste and will eat anything. America is also always trying to call all the countries together to "discuss problems" even though he can't face any of the very huge problems he's caused, and is always causing more than he's solving. It's later revealed that America has at least 238 weaknesses, one of which is Dora the Explorer.
Basically, America is Cancer. He can't own up to anything and he's fundamentally unreliable. He's the baby of the group, younger than all of the other countries. Really, what America needs is for someone to discipline him once in a while but he feels hurt at the slightest criticism.
Leo: Faye Valentine (Cowboy Bebop)
A woman with no past, Faye is defined by the lovers who betray her. Faye has to remake herself with a family, friends, or a community to help her.
What defines Faye as a Leo, I believe, is that despite being in heavy debt, the group always having nothing to eat, and caught in dangerous situations all the time, we see Faye doing high femme Leo things all the time, like painting her nails, doing a face mask, dressing fun, and spoiling herself in other ways.
If Faye weren't a Leo, the character we perceive might be much more tragic than what we get.
Virgo: Ryou Bakura (Yu-Gi-Oh! Duel Monsters)
Ryou is always doing little Virgo things, like making little dolls, writing letters to his dead sister, and researching the occult. Actually, we know almost nothing about this character because we can never be 100% certain that, when we see Ryou, it's not Yami no Bakura pretending to be him.
But from Ryou's deck, we can see his personality. His strategies are extremely tight and well calculated. He's also an isolated figure who wishes his friends were a little more invested in him.
Slightly cold, an analytical thinker, and extremely underestimated in almost every season, Ryou Bakura is a Virgo.
Libra: Soubi Agatsuma (Loveless)
The first time we see Soubi, we can already tell how codependent he is because he's literally stalking a sixth grader after his partner ghosted him. That's how Libras are. They get left by someone and they're on the next thing immediately.
One of the key plot points of Loveless is that we can never pin Soubi down. We hear that he's highly manipulative and cruel, but to Ritsuka he just seems really nice. Whatever his actual personality is like, he's always around and down to hang out when Ritsuka wants to. Not to mention, he's in art school but only paints pictures of butterflies-can you think of anything more Libra?
That's pretty Libra. They're always around, even if their ex lover comes back and their loyalty is completely undecided. It's just that you'll never figure out who they actually are.
Scorpio: L (Death Note)
There's a reason that L has no name and no face, why the surveillance to the building he built was so ridiculously high, and why he never ever talks about his past: it's because he's a Scorpio.
L doesn't just continually test Light in all their interactions, friendly or professional, because he suspects him of being Kira. He does the same thing to Aizawa for no reason. L is super paranoid and distrusts everyone because that's just the way he is. Remember that, before the events in Death Note, both kids L grew up with, A and B, were driven crazy by his antics.
One thing you'll notice is that L doesn't rely on hard evidence for his cases, but a gut reaction. If he were a Virgo, maybe he'd be interested in numbers. However, he is a Scorpio and all he really wants to do is psychologically investigate, interrogate, and manipulate his victims.
Sagittarius: Edward Elric (Fullmetal Alchemist)
Now, there's nothing in the canon that says Ed is a Sagittarius but we see him celebrate his birthday at the first snow fall in the northern hemisphere, which is usually a marker of Sagittarius season. And what sign would be willing to cross fate as much as Ed does other than Sag?
When Ed fucks up, he fucks up big. And he doesn't care how small he is-he has big dreams. Despite all the tragedy that happened to him, he says in one episode that it's learning from your mistakes that gives you a "fullmetal heart."
Sagittarius is experimental and Ed is innovative with alchemy because he's experimenting all the time. He's extremely well read and does well in an institution, but the brilliant things he's responsible for definitely don't come from some book.
Capricorn: Victor Nikiforov (Yuri!!! on Ice)
Victor didn't become the top figure skater of his generation by dawdling. When he was younger, he probably had to put in years of intense and rigorous discipline to build up his craft. When we meet him, however, we don't meet a Capricorn bloodthirsty for success. We meet a Capricorn who has already achieved, climbed his mountain, and is set for life.
Despite being only 27 or 28, Victor seems older and his seniority is a defining trait. He's too old for what he does now so he's looking for the next thing.
Capricorn mature backwards, acting like old people when they're toddlers and like children when they're old. We see Victor acting like a kid most of the time but, when we look at his decisions, they're surprisingly mature.
Aquarius: Matt (Death Note)
I was going to do Haruki from Ouran High School Host Club for this but couldn't resist picking Matt, despite the overrepresentation of Death Note characters in this article. It's just that Matt is so Aquarius. He's only in, like, 4 seconds of the anime and 9 manga panels. And that's the thing about Aquarius. You don't really see them.
When we do see Matt, he's making dirty jokes and playing video games. He's really chillax and doesn't seem to give a shit about the main plot at all.
It's easy to assume that Matt is always like this. In the Death Note 13: How to Read, we find how that the only reason Matt is third in line to become L is because of his apathy. Like any Aquarius, Matt is simply too cool for school, even a school that trains orphans to become professional detectives.
Pisces: Yagami Light (Death Note)
Last Death Note character, I promise. Light, like every other Pisces in the world, intends to sacrifice himself for the greater good. Notice that when Light tells Ryuk that he wants to become the god of a new world, it doesn't bother him when Ryuk points out that he'd be the only asshole left. That's because he's a Pisces. In his head, he's already mourning for his great sacrifice of morality.
No matter what Light does, no matter how ego-centric, he always defines what he's doing as a great sacrifice. He's willing to ruin his life, to sacrifice some members of his family, and to be generally really unhappy because he sees himself as a martyr. That's the only way for him to reach God, in his book. Light has no desires of the world. He's not interested in dating, junk food, or even money. He's only interested in his greater purpose of dying the slowest death possible.
