One day Sakura Avalon accidently stumbled upon the Clowbook in her father's study. And with her unknown powers, she was able to open the Clowbook. Summoning the Windy Card, all the other Clow Cards were blown away. Emerging out of the Clowbook was Keroberos (Kero for short) Guardian Beast of the Seal. He gave Sakura the Sealing Wand to capture all of the Clow Cards. Sakura was off capturing cards with new found friend Kero and soon to be ally Li Showron.