Meet Youko; or, as I like to call her, the Official Spokesgirl for the MoonMagnet Boy™ Fanclub. ^^;
She happens to be my favorite minor character in CCS.
Youko is actually an anime-only character, she appears in episode 14 "Sakura, Touya and Cinderella" (there is no Cinderella play in the manga storyline). As far as I can tell, the sole purposes of the Cinderella episode are Touya Character Development and Hitting Viewers Over the Head with T/Yness. It basically establishes the fact that our dear MoonMagnet Boy™ is, well, Seijou's Most Desirable Bachellor (I'm on a roll with the nicknames tonight), but that he simply does not want any of the dozens of girls throwing themselves at him. And then, once that is established, it poses a very good question: why? Why doesn't he want any of them? Well. We know, don't we? ^.~
Anyway, Youko is one of those dozens of girls crushing on Touya, and it is through her and with her that I found out about TouyaxYuki (this was the second full episode of CCS that I watched). She is not, however, just one more of them. Youko is presented as a popular, pretty girl. Not just that, she's obviously not a ditz, as she's in charge of their class' play. And, despite her feelings for Touya, she doesn't drool over him the way most of the other girls do. Which is probably why Touya likes her (he does... just not /that/ way). When her friends teasingly suggest that she and Touya would make a cute couple, she vehemently denies having any feelings for him. Perhaps this is just me proyecting, but what that told me is that she doesn't want to be seen as "part of a herd", so to speak.
So Youko plays Prince Charming to Touya's Cinderella, disaster ensues (in the form of a Clow Card that makes the set literally disappear under their feet), and Touya saves her (or tries to) while putting himself in risk. Many cow-eyed looks and "Kinomoto..."s on Youko's part make it pretty obvious that at this point she's finally wiling to admit to herself how she feels about him.
I seriously thought they were setting Touya up for a girlfriend while watching all this for the first time (remember, this was only my second full episode).
Then comes the Defining Moment. At the very end of the episode, Sakura asks Yukito where her brother is. Yukito answers that To-ya is busy right now. (And, I might add, I got the distinct impression that 1. Yuki knew exactly what was happening, and 2. he wasn't particularly concerned by it). The scene changes, and Youko and Touya are up on the school's roof. She tells him that she likes him, and his eyes widen (that means that he was probably very shocked, because this is Touya we're talking). He lets her know that he doesn't feel that way about her, and she wistfully asks if there is someone that he likes. He admits it, and she wipes her eyes and says that she expected that (well, that's what she says in the mexican dub).
Let me pause here and say that I simply adore this scene. It's one of my favorites in the entire series. Touya doesn't say much, but the way his eyes widen and then soften as he lets her down makes it very evident that he really didn't want to hurt her. And then there's Youko. The expressiveness of her face is amazing (this type of thing is exactly the reason I love anime). You can see her face falling as Touya lets her down and you just know her heart is breaking. But the amazing thing is the way she doesn't give into it, the way she wipes her eyes and smiles at Touya. It's such a wistful smile and it's simply beautifull to watch.
Then dancing starts down in the school's yard, and she asks him to dance with her. He agrees, which is obviously a very rare move on Touya's part (Sakura is amazed to see her brother dancing). When it's time to switch partners, Touya refuses to go on dancing, saying that he only promised to dance with her. Too cool for words, ne?
(Small digression: at this point Touya goes back to where Sakura, Yuki and company are waiting, and as Yuki walks off to dance with Sakura, he stares after them with the cutest, most lovey-dovey expression... this when my brain started screaming Wait a minute!!!! Touya is in love with Yukito!!!)
That's it for Youko's part in Cardcaptor Sakura. How she made such an impression on me in less than half an hour of screen time, I don't know, but I've even turned her into the most important supporting character in my ongoing fic about how Touya and Yuki's relationship develops.
Actually I do know why I like her so much. She's not just there as a vehicle for Touya character development. The way I see it, she's there to give us fangirls someone to relate to. Afterall, it's understandable (to us) that a girl would crush on Touya. The difference is how she deals with it. Kaho had him and not only let him go, she broke his heart too. And Nakuru... Nakuru is basically a bitch to Yuki, which in some fans' eyes is unforgivable (I rather like Nakuru myself, but I do want to grind her neck when she's giving Yuki those smug, challenging looks). Youko on the other hand... Youko accepts that she must love Touya from afar.
Any similarity to the way us fangirls love Touya is purely coincidential, I'm sure. ^.~