Tsubasa Reservoir Chronicle is the new series by Clamp with lots of characters from their past works. The hero is Syaoran and the heroin is Sakura. Meiling is still ignored from the entire manga.
Sakura is the princess of the country of Clow, Clow Reed is Sakura's father, Syaoran came to the country with his father, turned out to be Sakura's father in CCS, for his job as a philosopher. Syaoran met Sakura when he was very young and is her best of friend. Syaoran's father later died, so he has to make his own living as a philosopher, to continue his father's will.
One day, Syaoran is at work, Syaoran finds out that there is a strange symbol at something he is looking at. Sakura comes along with a packed lunch, planning to express her feelings to Syaoran. She notices the symbol and recognises it from the dream she had. Suddenly, Sakura loses her senses and a pair of wings stretches out from her back, an opening opens to let her in, Syaoran tries to save Sakura, but she is already nearly drawn in. He jumps and pulls her out, her wings break apart and are lost. Someone is trying to kidnap Sakura to get the powers of her wings, the powers are unclear, but they point the direction of something unknown. Syaoran brings her out and sees Yukito, a fortune-teller with great powers, He knows that each feather of the pair of wings contains a fraction of her memories, without her memories, she would die. The feathers are spread to different worlds. Yukito sends him to another world to a witch to try and save the princess' life. Syaoran has to go to different worlds to save her life.
In another world, Fye D. Flourite wants to escape from the king of his world, he leaves his creature, Chii, there to inform him when the king awakes again. Then he sends himself to the witch for help.
In Japan yet another world, Kurogane, a samurai, kills everyone who tries to break into the palace. The princess, Tomoyo, summons him to her. She dislikes him for killing people, so she puts a spell on him, when he kills one person, his powers would decrease. She then sends him to the witch to meet others who fight for different purposes, to let him learn.
The three, or four (including the unconcious Sakura) see the witch. The witch gives them a creature, Mokono, that brings them to different worlds at random, but they each have to pay their price, teh most valuable things in their lives. Kurogane has to give her his sword and Fye has to give her his symbol of spells. Without hearing his price, Syaoran agrees to give anything he could. The witch has to take away Sakura's memories of Syaoran from him, still, he agrees.
She gives them the creature, and they are off to another world. Syaoran finds a feather on him, enough to keep Sakura alive for a short while. Mokona has also the powers to sense the feathers of Sakura's, so the trip is easier. Syaoran needs powers to fight for Sakura's life, later he gains powers from a creature of fire, which is one of the strongest. Fye and Kurogane assist Syaoran in the journey and this is just the start of their journey.