First off, I want you all to know these pictures are from and in my opinion, this is the best Cardcaptor site out there! Now on with the story....
Once upon a time there was a fourth grade cardcaptor named Sakura Kinomoto. Sakura had a major huge crush on a boy named Yuki. One day, a certain boy by the name of Li Shaoran showed up at her school. He was a very intense looking boy, who rarely smiled. Sakura and Li basically start off on the wrong foot. Li acts like he is better than Sakura and tells her she's not cut out to be a Cardcaptor. However he eventually admits that he is wrong, and she may actually know what she is doing (shocking! ^_^) So, they grow to be friends and partners.
In the original version (it has yet to be released in the US Version) It is thought that Li likes Yuki (Julian) and Sakura does too. However, he later realizes the one he truly likes is Sakura. He tries to tell her a few times but he is always interrupted in some way or another. In the mean time they grow closer, in fact she calls him Syaoran-kun, a name usually only family calls him.
At the end of the Sakura Card series, Li has to return to Hong Kong. Sakura is very sad to see him go but makes him a bear (Syaoran).
She gives it to him in sort of a "you better come back" way and then he leaves....I also read that he returns years later and they live happily ever after :)