I expect this explanation to love you, I have made all the one that I have been able so that it is the best summary of all and the thing, most faithful to the movie!!
The Film starts with Sakura, Keroberos and Yue to a scene of very good action. Here Sakura is seen wearing the blue dress with yellow ornaments. The three of them are fighting every type of monsters. On a side the Tomoyo is recording everything.
It has passed time from the course of Shaoran to Hong Kong. In the house of Eriol they are building a fairground and there is a scene in which it is seen in a card of Clow, but it is not distinguished well.
Sakura and her class are working in a play for a festival of summer, named the festival of Nadesiko. In the work, Sakura is the princess and Yamazaki is the prince. A day, when keeping walking with the Tomoyo towards an essay through the fairground, Sakura feels the presence of something and goes out running to see that it is. Suddenly she runs into Shaoran and Meiling. She does not know whether the presence that Sakura noticed would be Shaoran.
After that, there are quite a lot of cute and pretty scenes in which Meiling is seen trying to leave alone Sakura and Shaoran so that Sakura tells her real feelings to Shaoran. They get on a water wheel, and Sakura tries to say her, but she does in the end not dare. Sakura invites to dinner at home his, but Meiling and Tomoyo had already remained, so single Shaoran is remained to dinner, at the house of Sakura there is not anybody, but in the moments in which Sakura tries always to answer, the first because of Kero and the second for Touya, is interrupted.
Meanwhile, without Sakura realizing, the cards start to disappear. In the moment in which she realizes, any longer there is not at all to do. When trying to use some card because she recovers the other cards that have been stolen, this also disappears. It seems to be that the cause of everything is a card of Clow that was never sealed. When the card acts, it does to disappear different parts of the city as houses, bridges... the city is slowly erased.
Sakura writes a letter, how much Eriol calls her by telephone (if you have seen some chapter of the Anime of Sakura in Japanese, you will realize account of his voice having changed). It results from he having already found out about what he is passing and explains to Sakura that it is what it is passing. Eriol tells Sakura that to recover the cards and to seal and to transform into card Sakura to the malignant card, she has to lose her most appreciated feeling.
A day, in one of the essays, Sakura uses the card to sleep to be able to use her powers against the malignant card, but can not catch it on the contrary she is taken more cards, when waking up the colleagues, by Yamazaki damage has been done in the left arm, because of that Sakura has done it to sleep and he has disagreed, Yamazaki gives the role to Shaoran since he knows the scripts quite a lot.
Sakura tells Shaoran what is what she has to make to the malignant card to recover the cards and to seal. She does not want to give her feeling, but she does not know any other way of fixing the problem. Shaoran tells her that it is what she has to make, that there is not any other way and he does also tell him that if he has fallen in love once of her he can fall in love again. When she hears him to say that, she goes out running crying. While she runs, she runs into Yukito. He asks her whether he wants to talk on what worries him. Yukito is transformed into Yue and Sakura explains her what happens, all that passes under a heavy rain.
It is the night of the play, Sakura is splendid, and after a magnificent scene of dance, how much the princess (Sakura) is going to confess her love to the prince (Shaoran), the card acts again. All the world of the theater comes out running, but they are erased by the card.
Now only there is Sakura, Shaoran, Tomoyo, Meiling, Keroberos and Yue. Tomoyo gives a dress (Pink) to Sakura, but she tells her that now there is not time. Tomoyo says her that if this dress is put, she will return, because whenever she has taken to one of his brought has returned. She gives another to Shaoran (Green) and she tells him that if he takes him put, he will save Sakura and turn her safe and sound. Sakura and Shaoran get on the Keroberos, because the card "flight" had disappeared, and go out towards the fairground. When arriving, Shaoran tries to capture to the card it alone, since his power is not of Clow, but he does not obtain it.
Shaoran is captured by the card and Sakura goes out to go to the aid of him. Sakura only had a card. The card that she had created in the last episode, the card of the heart with wings. This says it that she does not worry, of everything coming out well. Now Sakura has to use her most appreciated feeling to seal to the card, but Shaoran is placed to the same trajectory of where the card was. That does that the feeling most appreciated of Sakura, which was that she loves to Shaoran, will break, making Shaoran forget his love for him for Sakura.
The eyes of Shaoran turn completely white. That breaks the heart to Sakura, but the card tells her that everything will go well. The bad card turns into the card: The hope. Sakura tells Shaoran (which was as a statue with the head goes down) that probably he does not find out about what she is telling him in that moment, but that she loves he. There is a great silence and suddenly, Shaoran says him that he also the owner. Shaoran lifts the head with a smile to his face.
Sakura jumps, towards Shaoran, while she tells to him:
"I love Shaoran".