When Sakura had used the Return Card to meet Clow Reed before he died he had said, "Seasons change and so do the people. No life is meant to live for an eternity." At the time, the young Cardcaptor vaguely understood what he had meant. She only knew that that phrase was Clow Reed's parting words to Kero and Yue so the two guardians would realize that after he died, they would have to accept orders from a new master.
Years passed and Sakura (a mature, older, wiser and more powerful magician) finally grasped the full concept of Clow Reed's words, as she too, would soon leave the world and the two guardians would have to part ways with another friend. Masters of the cards changed, masters of the cards died and new masters would be chosen. That was the sad truth and Sakura had to make preparations for the next candidate that would be suitable for the job just as Clow Reed had once done for her.
The only issue was figuring out who would be appropriate. Sakura never figured out how Clow Reed came to the conclusion that she would be a Cardcaptor. After all, she was born hundreds of years after he had died! How could she ever accomplish that task?
The magical powers passed down to Sakura's descendents made them eligible for becoming the next suitor but magical abilities were not enough to care for the cards and the guardians that came with the responsibility. In the end, all she knew was that the next person, no matter who they were, would find to love and cherish the cards, Kero and Yue as much as she did.
It was the day where a new Cardcaptor was born and the reign of the predecessor ended. History seemed to be repeating itself as the new candidate, chosen by the Beast of the Seal himself (after he had woken up from a thirty-year nap), had opened the book and accidentally scattered the Sakura Cards all over Tomeoda City with the use of Windy.
As the boy captured the Fly, he looked at his star wand, the Sakura Card in hand and then at Kero with a sour expression. "Why does everything have to be pink?"
Before Sakura died, she remembered the time in her life when Clow Reed's reincarnation, Eriol, had to create unusual situations for her magic to grow. Sakura had assured herself that there was no possible way she would ever cause trouble for the next child.
The only thing she forgot to consider was if the next Cardcaptor would be a boy. It seemed, like Clow Reed, she would be of a nuisance to the card heir.