Cardcaptor Sakura: Master of the Clow, Vol. 3(1999)

Clamp

Capturing Cards was only the beginning...

Once upon a magic night, an English sorcerer mixed Western wizardry with Eastern enchantments to create a magical deck of cards called the Clow Cards. These cards were hidden inside a dusty old book for decades, their powers virtually wasted. Then one fateful day, a young girl named Sakura Kinomoto discovered the book in her father's library. When she opened it, however, the Clow Cards were gone--and so was life as she knew it. The book's magical guardian, Cerberus, declared Sakura the Cardcaptor, and after many exciting adventures, she finally retrieved all of the cards. Now Sakura has earned the title Master of the Clow.

The mysterious presence of Clow Reed continues to test Sakura with new dangers that require all of her energy to defeat. And this means that she no longer has the energy to support Yue, the Guardian of the Moon, and now he could disappear forever! Most of the time, Yue stays in his human form as Yukito, the boy Sakura has a crush on, but now that Yue is weakening, Yukito is deathly ill. If Sakura can't find a way to help him, boy and guardian will disappear forever!