A long time ago...

"Hurry, Yue! Master can't take it any longer!"

"I know, I know! But I can't find the right book! Master and I didn't touch on that subject quite yet..."

The castle was in chaos now that their high and mighty ruler was attacked by his one and only nemesis. Darkness flooded throughout the beautiful and tranquil little kingdom and made it ugly and agitated. Confusion had spread throughout the land from the news of the All Powerful being assaulted.

The Master's enemy was always jealous of him because he was always one step ahead of him. They had their disputes once in a while, but they were always angry with one another. There were many other sorcerers, but these two were the most powerful.

...Ugh...Keroberos...

"Hold on, Master. Yue is searching for the textbook that contains the healing potion to relieve you of your pain. Just hang in there." Hurry, Yue, hurry...

Keroberos, or just Kero, was a magical lion-looking creature with armor of some magical sort. He had great, yellow wings like an angel. His master, who was the ruler of their kingdom, created him. Yue, on the other hand, looked like a human with long, white-grayish hair. He, too, had wings like an angel, but his were light gray. 

"I found it, Kero!"

"Great! Now turn to the dark magic section and look for the Anti-Toxin spell."

"Found it! Ok, hold on. I have to chant the spell."

'Ugh...Please...Hurry...'

"Hang in there, Master. Yue, hurry!"

"Power of magic, power of the Clow,

Relieve Clow Reed of Toxin now!"

"It's working, Yue! Master is recovering! Now, grab his staff.

Yue handled the long and magical staff. The Master's ancestors wielded this particular staff. It was forged in the greatest fires humans have ever seen. This staff was the greatest staff ever known. At the top end of the staff were a sun and a moon combined. It was a golden artifact and, if not handled properly, was able to bring mass destruction.

"Ok. Now chant it once more and point the staff towards Master."

"Alright."

Yue did what he was instructed. An illustrious light shot from the tip of the staff and hit his master's heart. At that moment, their master's eyes opened as wide as they could. As soon as it started, it ended just as fast.

"Master Clow Reed, how are you feeling?"

"I'm fine. Thanks to the both of you, Keroberos and Yue."

"We're glad we could help, Master."

"I fear that my time is coming to an end," Clow Reed said.

"No! How could this be possible?!" Yue asked.

"Calm down, Yue. Kero, you'd better listen too. I will explain everything. You see, everything that lives must die sometime. It is my time to leave soon."

"This cannot be happening!" Keroberos yelled.

"Can't we search for the ancient stone of immortality?" Yue asked desperately.

"Ah, yes. The ancient stone of immortality... Yue, as I said before, all living things die. Those people who have found the ancient stone of immortality have tampered with life itself. Therefore unbalancing life's existence. Don't you get it, Yue? It is written in everyone's fate. But let's say that we do find the mystical stone. First, I'll focus on the bright side. If I use it, I will surely become immortal. You two won't need it because I created you to live forever."

"You see! Kero and I will live forever! You said so yourself that all living things are destined to cease."

"Ah, that is where you are wrong," Clow Reed said." I created you because I needed help around the castle. I used my magic to create you two. In other words, you are one hundred percent magic, which means that you may only die when your magic runs out-"

"But we get our magic from you!" Keroberos interrupted. " You are our source of power. If you're gone, then where will we get our magic? No one is strong enough to help even one of us!"

"Again, I have another explanation," Clow Reed said. " Kero, you and Yue will be in eternal sleep protecting my most precious book ever."

"The Story of My Life, your number one seller?!" Kero asked.

"No, no, no. It is a book that is still in progress," Clow Reed explained. If my vision goes as I saw it... Kero and Yue would have a very big task at hand.

Kero had a puzzled look on his face.

"You see, Kero," Clow Reed said. "You have asked too many questions I ended up confusing you. I'll tell you more about the book as I get more progress on it. Don't worry, I'll finish it and have instructions for the both of you. You two need to relax more. Be carefree and enjoy life!"

"Sorry, Master," Yue said, "But I just can't relax while I know your greatest enemy still lives."

"Now, now," Clow Reed said. "I'll take care of him. He just caught me off guard. Besides, I am very much stronger than he is. Remember that."

* * *

Months passed and Clow Reed had created more magical creatures to help him. These creatures helped in his everyday activities such as cooking, cleaning, etc. Clow Reed didn't make them as powerful as Yue and Kero, but together they could put up quite a fight against those two. It was good thing that they were loyal. But soon, some of them had grown disobedient...

"Ugh! Firey, quit it!!" Kero yelled at one of the creatures. "You know, Yue, one of these days I'm going to fight back at these troublesome beasts! I don't care how much trouble I'll be in with Master!"

"I know how you feel, Keroberos," Yue agreed.

The creature named Firey (as its name suggests the thought) had powers of fire. It was one of the four strongest creatures. The other three were the Windy, Earthy, and Watery. All of them were elemental creatures, which made them stand out from the other forty-seven.

"Firey!" Clow Reed shouted. "Stop this at once!"

Firey stopped being a troublemaker at the sound of its master. It just left the room very quickly.

"Master, I cannot stand this any more," Yue said. "Just earlier, Bubbles kept on making the floor slippery and making me trip and fall."

"I was afraid this would happen," Clow Reed explained. "I will trap these creatures into cards. I'll call them after me, which will be Clow Cards. From then on, whenever we need a creature, we will summon them from the card they are in. When they are not needed, we will store them in a book. I will grant you two the power to summon these cards. Use your new powers wisely."

Clow Reed gave new magical powers to Yue and Kero with one motion of his hand. A bright light glowed around the two for a moment then disappeared. Clow Reed went off to start trapping the creatures into Clow Cards.

* * *

A month went by and Clow Reed became weaker and weaker. Being their source of magic, Kero and Yue were soon losing little bits of their magic. They could tell that his time was almost ending, but they did not want to think that.

It's just a minor illness...Yue was trying hard not to see the truth.

"Kero, Yue," Clow Reed said. "I am afraid that my time is now. Please take care of the castle and most importantly, the Clow Cards."

"No, Master, you are not dying!" Yue screamed. The thought of their creator dying was heartbreaking. "You can't!"

"Yue, I know you and Kero care about me the most, but you must be strong," Clow Reed said. "Be strong Yue. I will always watch over you."

"But Master..." Kero said. He was still in shock.

"Expect the unexpected," Clow Reed informed the two. "Don't be so sad. I will always be with you. Stay stro--"

"No!!!" Yue and Kero yelled as their master passed away.

Tears flooded in their eyes. Their hearts, broken. Their minds, full of sad thoughts. Their souls, lost.

"Keroberos," Yue said, breaking the silence. "We must do Master's last wishes."

"You're correct, Yue," Kero agreed," we must."

Keroberos and Yue stayed at the castle, guarding it as well as the Clow Cards in the Clow Book. After a year, Keroberos and Yue saw Clow Reed in a dream. In each dream he gave the person a mission. Kero was to transform into his little form and guard the Clow Book from inside. Yue was to watch over the Clow Book. If anything was to happen unexpectedly, Yue was to hide somewhere well hidden, but every once in a while checking up on the Clow Book and Kero.

Present day...

The castle became a part of a tourist spot. Yue and Kero fled with any evidence of their existence. They traveled to an abandoned house no one ever went in. The two decided that Kero should go back inside the Clow Book and prevent anyone from opening it. Yue was to take a human form and watch over the Clow Book from outside.

"We must not let anyone find the book," Yue said. "But if someone does find it, prevent them from opening it."

"Right," Kero said.

"Wherever you and the book go, I'll go," Yue said.