The Clow Book was created by Clow Reed, the Sorcerer. He created the book to hold the Clow Cards.

Clow Reed assign the task to keep an eye on the cards to Cerberos, the clow guardian and to prevent the cards become evil.

The Clow cards are powerful enough to destroy the world if they torn evil. The Card Captor is the only one who can capture the cards if someday the cards are scattered all over the world.

Here is where Sakura enters the scene!

Here is one of the cards inside the Clow Book!

Hope!