This is another one of the mangas I read online and then went to buy for myself in "analog" format (like Death Note).
There is an "Ultimate Edition" released by Tokyopop USA that has two volumes in one book and bonus material. I like those, they take up less room on the shelfes. Unfortunately the third one seems to be sold out - if you find one at a reasonable price, please tell me!
Volumes: 23 (26 anime episodes)
Mature content: emotional and physical abuse (but only little blood is seen)
There's a story about the twelve Chinese zodiacs: Once upon a time "God" (or the Jade Emperor in other versions) called the animals for a banquet. They came and had a good time, and those who attended became the zodiacs: the rat/mouse, the ox, the tiger, the rabbit, the dragon, the snake, the horse, the ram/goat, the monkey, the rooster, the dog and the pig. The cat was invited, too, but the rat deceived it, so the cat missed the meeting and is not a part of the zodiac.
Fruits Basket (short: Furuba) is a shojo manga. It's about the girl Tohru Honda. Since her mother died in a car crash she lives in a tent. But then she is discovered by her classmate Yuki Sohma and invited to live with them (he lives with a cousin and they both fail at housework). It turns out that some members of the Sohma family carry a curse: they turn into one of the zodiac animals (including the cat) when hugged by a member of the opposite sex or when being stressed or weak. One after the other Tohru gets to meet all of the "zodiacs" and grows quite attached to some of them. But shape changing isn't the biggest problem that comes with the curse...
The biggest downside of this manga is once again the female lead. I don't know why these kinds of girls are so popular in manga and anime. Tohru is as empty-headed and uninteresting as it gets (even worse in the anime than in the manga), but everyone adores her because she's "cute" and "nice" or something like that. The most intelligent things she's saying is stuff she learned from her late mum, other than that she's mostly just agreeing or saying sorry.
Another strange thing about Fruits Basket is Akito, who is supposed to be the "God" out of the Zodiac legend. Head of family or not, how the zodiacs are treated by him is out of it. In every normal community the police would be called on him. It's not only mindgames, he imprisons them, and abuses them psychologically and physically, quite often ending one of the zodiac up in hospital, and even taking out an eye. But still everyone loves him. There's a major spoiler in the end (in the manga) that I won't give away here, but that doesn't make it any better. I have zero sympathy for that person and I still think he's one of the worst villains and gets off with an undeserved happy end.
Oh, and literally everyone in this story has issues. And most of the parents shouldn't have had kids.
The rest is awesome though. It gets rather angsty at times and is more bittersweet that you'd expect from a shojo. It will probably make you feel glad you were born into your family though and not the Sohma's.
There are many characters, but they are introduced at a pace that's not overstraining.
My favourite characters are Hanajima (one of Tohru's best friend, dressing in Gothic Lolita style and able to sense "waves"), Hatsuharu (the ox) and Rin Sohma (the horse) - I love their Goth/Punk style of clothing - Hatori (the dragon) and Kazuma (who adopted Kyo when he was little). But most of all the cat zodiac Kyo - after all I love cats (and hate leek). He also very much reminds me of someone I know.
The chibis are extremely simple, but after getting some used to it, that's fine.
Everyone has a kind of symbol assigned to them, for the zodiacs it's their animal of course, Tohru a onigiri (riceball), etc. It helps recognizing them and their speech bubbles.
And the animal forms of the zodiacs are just too cute!
I would recommend to read the manga instead of watching the anime. Not only is the anime missing out some of the most interesting characters, the end is also quite different and has a very unfinished feel to it.