When our little wolf first appears, he GLARES at everyone, especially Sakura. He rarely talks, and he just glares, and glares, and glares even more...He tries to force Sakura to give him the Clow Cards, since the Li clan IS the rightful owner. He goes as far as nearly twisting her arm when...TOUYA TO THE RESCUE! And Syaoran meets his match. And that, my friends, is the start of the GGC(tm). Yup, you guessed it, it's the Great Glaring Competition! Since then, every time Syaoran and Touya meet, the GGC commences...
When he appears as the rival cardcaptor, Shaoran says Sakura can't handle the clow cards. True, he helps her a bit, THEN he insults her, saying that she doesn't know anything. He's always saying that Sakura is a pathetic girl, and disregards the fact that Sakura had no training whatsoever, unlike he did...PLUS he also calls Cerberus, Sakura's guardian beast, a stuffed toy. And so, there's another one of Syaoran's sparring partners.
Syaoran is actually Chinese, living in Hongkong. He was sent to Japan by the Elders of the Li Clan, since he is a DIRECT DESCENDANT of Clow Reed, the maker of the Clow Cards.
The Li Clan is a RICH clan in Hong Kong. Being an only son, a lot of responsibility is cast on him. But no, he isn't an only child. He has four older sisters, Fanren, Fuutie, Feimei, and Siefa. His mother, Yelan, is a very beautiful and sophisticated woman. His father died when Syaoran was VERY young. I guess the reason of his initial attitude is...well, with all his training and strictness of the family, you know what I mean. In Japan, he is accompanied in his apartment by Wei, his butler and trainer.
But as the series keeps going, we see him talking more (eventually smiling more)...and even helping Sakura to get some cards, when he thinks that she deserves it. I guess, Sakura's friendliness is REALLY contagious. And this also goes to show that Syaoran isn't really purely mean: his good side slowly surfaces. He eventually becomes one of Sakura's friends, improving to the point that he can cheer up even the ever-cheerful Sakura when she feels helpless and cries.
Shaoran totally LOVES chocolate. He'll eat chocolate at any opportunity he can get. He's VERY good at cooking, too, even at his young age of 10. His best recipes are those of New Year special delights like deserts and cupcakes.
When Syaoran goes catching cards, he wears a green robe (SUGOI!) with a matching cap. He also weilds a sword, and he also uses ofuda (seals/charms) controlling elements. His power is of the moon. He can use Clow Cards like Sakura, though he can't make them into card form himself.
Shaoran-kun is a bit gullible. He and Sakura are the only ones who fall for Yamazaki's stories...But, in reality, Shaoran is intelligent. He has to be! I mean, he's a leader of a whole clan, for crying out loud! Anyways, he's very good at math (unlike Sakura), but he doesn't like studying the Japanese language very much. He's also very athletic. He's great at sports and martial arts...he's VERY good at martial arts. Shaoran also runs in the 100m dash, tying with Sakura, and he's also a good marathon runner.
Syaoran is a TOTAL BISHIE! No, really, he is! With his unruly chestnut brown hair and glaring amber eyes...*faint* He's also very kawaii when he blushes and stammers. I'm surprised Sakura didn't fall for him at once^_^
Notes about the name
Xiaolang means little wolf...sugoi, ne? Anyways, of course, being Japanese, it's pretty hard for everybody else in Japan to pronounce his name. That's where we get Syaoran and Shaoran...Though he's actually Li-kun to nearly everyone (even Sakura, at first), he's:
"Xiaolang" to Meiling and Family
"Gaki (brat)" to Touya and Kero-chan
"Shaoran" to Sakura (latter part of the series)
"Syaoran-sama" to Wei
"Cute descendant" to Eriol (sometimes)