If I had to describe in a single sentence what the underlying meaning of most any magical-girl story was, it would be this: how to remain a good person in a troubled world. Most every magical girl starts off innocent, and the challenge she's faced with is how to preserve that innocence. Not in the sense that some fiend is going to despoliate her, but in that she'll be confronted with all manner of evidence that it's easier to just be a bad person, a power-hungry person, a person who gets drunk on power and never notices the hangover. Her challenge is to continue to believe in the good in both herself and others, even when she has reasons not to.
Cardcaptor Sakura spends its first season showing us how such a person comes to exist in the first place, a tactic that might not seem wise at first. After all, when someone is surrounded by good people who care sincerely for her, what's there for her to push against other than the synthetic obstacles the story throws in her path? But I'd wager that it matters: it lays a foundation for understanding how someone can not only be good but stay good. And given what a fundamentally sunny and positive story Cardcaptor Sakura is, that approach makes sense.
Sakura's mission: to pick up the pieces
Sakura begins with the staple setup for most any magical-girl story, the broad outlines of which we all know by now. A young girl — anywhere from a preteen to a teenager — is given great power by an avatar or companion, all in the name of accomplishing some mission or keeping the world safe from such great danger. At first the girl is scared and hesitant: she doesn't know how to wield her powers properly; she's terrified of the unknown dangers she's being asked to face down; she's worried that having her double life exposed to her friends or family will mean ostracism for her or danger for them. But over time she conquers all of these obstacles.
In Sakura's case, the girl is ten-year-old Sakura Kinomoto, and I sometimes wonder if the way she was assembled was as a point-by-point rebuke to Usagi Tsukino in Sailor Moon. She's a pre-teen to Usagi's teenager; she's scholastically competent and physically adept (unlike Usagi); and her father regards her as a treasure to be cherished (instead of her parents mostly dismissing her as a problem to be solved). She's the kind of kid most of us wouldn't mind having for a little sister — except maybe for her own big brother, the stolid and somewhat sullen Toya (a character stamped from roughly the same mold the creative team, CLAMP, would re-use later on for Dōmeki in ×××HOLiC). But their rivalries are more in the vein of comic-relief material than a sign of major rifts in the family.
One night Sakura mistakenly opens a Pandora's box of sorts — the fact it is something she finds in her own house is glossed over for the time being — and looses a deck of magical cards into the wild. Unlike Pandora before her, though, she's tasked with the job of cleaning up the mess she's made, lest great calamity befall the world. Her taskmaster is the "Keeper of the Seal", Cerberus, who resembles a little yellow stuffed toy lion and is rather irked at how his minimal levels of power at this time only allow him to incarnate as something that innocuous ("Kero-chan"). Part mentor and part best pal, he provides Sakura with a magical wand to track down and retrieve each of the cards, and comments on all her progress, or lack of same, in a chirpy Kansai dialect that's all the funnier for being so incongruous.
Sakura's quest doesn't just bring her into contact with a slew of cards from the deck, each with their own self-describing power ("The Windy", "The Float", "The Illusion", "The Fight"). It also brings her into contact — and sometimes collusion, and sometimes conflict — with a gallery of other characters. On the collusion side, there's her friend Tomoyo, who uses her apparently bottomless pool of funding to garb Sakura for combat — through this the show makes a running gag out of how she's in a different outfit each time a new card turns up — and film the results for posterity. On the conflict side, there's Li Syaolan, a stern-eyed young man also hunting down the cards, who arrives from abroad and in time goes from a competitor with Sakura to a co-conspirator. The way both Syaolan and Sakura have rival interests for Yukito, a friend of Sakura's brother, becomes an unexpected way to bring Syaolan closer to all them and reveal what another show might consider his weaknesses but which here might be better called his sensitivities.
Standing out of the shadows of its successors
Generally speaking, there's two kinds of good shows: the kind that build solidly on their predecessors without innovating a great deal, and those that use what came before to produce something genuinely new. Puella Magi Madoka Magica would be a good example of the latter; Cardcaptor Sakura is — at least in its first season — one of the former. We know what the formula is and we are not surprised a great deal by how it plays out, but it plays out with enough verve and spirit that it works. And every now and then there's a moment of genuine comic invention: one episode, which involves a card which shrinks Sakura down to a few inches in height, unspools more or less as you'd expect — but the zinger at the end, involving Kero making the most of a snack, is truly funny.
Another thing I've come to notice is how the very things that make a given show appealing to one audience can also work against it. Sakura was created mainly for younger viewers — both boys and girls, I would argue — and its general atmosphere of positivity and sweetness is one of those things you either find endearing or cloying. I'd make a case for the former, in big part because the show knows how to sustain such a thing sincerely; it's not something maintained for the sake of allowing Sakura to be sympathetic despite what she actually does. She's a good kid not because the story insists on it, but because she lives up to the role, and doesn't abuse what she's been given, either in terms of the cards' powers or the people around her. The people who fear and distrust her at first soon come around to her side, because they can see she's not their enemy and has nothing up her sleeve.
That said, I suspect a big part of why the show doesn't (at least not yet) confront the full implications of having someone like her command this kind of power is not merely because she's a genuinely good person, but because smart story construction dictates that to plunge into something that thorny too early on is unwise. And again, I don't see this as a limitation of the material — at least, not as far as its first stretch of episodes goes. Something that major is not something you can plunge into face-first in a show like this, although I do argue that dealing with it at some point — and dealing with it honestly and responsibly — will leave you with a better show, even a better "kid's show", than a show that simply chooses not to because that makes things too complicated. At some point it had better happen, but I'm not upset it hasn't happened yet.
Given that Sakura was released around fourteen years ago, one could make the case that it's part of a wave of stories in this vein which have since been superseded by revisionist / deconstructionist productions like Madoka. But I don't see it that way. The two are part of a continuum, no doubt about that, but it's unfair to a show like Sakura to see it as being rendered obsolete by later work. For one thing, the later work could scarcely exist without the former; for another, the two kinds of work satisfy broadly different things. A show that does a simple, focused thing competently and enjoyably is rare enough, and in that sense there's no wrong in calling this show a classic and a treasure.