Many different oneshots published in Newtype Magazine, each involving xxxHOLiC and another CLAMP title.

Kindai Mahjong:
A short gag "series" that Clamp draws in various magazines. This one came from Kindai Mahjong, a gambling magazine. It features a certain blond bishie from Gohou Drug along with a couple of other characters from xxxHOLiC.

From Be With You Scans:
A collection of bittersweet tales of all the different shapes an unrequited love can come in. Why is it so difficult to confess your love? Why is it that another person can affect someone else so strongly? When a powerful man is fickle, he is allowed to be. But if a woman is unfaithful, she is called a tramp. Koi tells the realistic stories of six different women of different ages, and completely different outlooks on life.

CLAMP School Detectives focuses on the exploits of Akira, Nokoru, and Suoh - 3 pre-teen sleuths - and their quest to make the CLAMP world safe for the girls in their class ...

In the future, the most popular game in the world is Angelic Layer. Contestants must raise and train their own 'Angels' (or fighting dolls) to compete in tournaments. Enter Misaki Suzuhara, sixth grade Angelic Layer prodigy. With her speed-type angel, Hikaru, many people think Misaki stands a chance at winning the championship. She'll have a lot of help along the way, but the road to victory will be not be an easy route, especially for someone as young as Misaki.
(Source: Tokyopop)

To honor CLAMP's 15th anniversary, CLAMP no Kiseki: The Ultimate Collection features full-color pages, exclusive material, 6 pages of new, never-before-seen manga, and limited-edition collectible figures!

Watanuki Kimihiro is haunted by visions of ghosts and spirits. Seemingly by chance, he encounters a mysterious witch named Y?ko, who claims she can help. In desperation, he accepts, but realizes that he's just been tricked into working for Y?ko in order to pay off the cost of her services. Soon he's employed in her little shop- a job which turns out to be nothing like his previous work experience!

Legends say that when it snows, it is because the snow princess is crying. A collection of five tragic tales, all connected by the bond of snow. Shirahime-syo is CLAMP's tribute to traditional Japanese form and storytelling.

From Clamp no Lumiere:
Murikuri is the story of a popular pig, a pervert santa claus and his high school girlfriend, nice aliens and many more... It does not make sense and I would advise you to not try to understand it. Murikuri is to CLAMP what special halloween is to the Simpsons, a collection of short gags.

From Tokyopop:

Kentaro and Takeshi are two freshmen who are periodically called upon to transform themselves into monster-battling superheroes, complete with capes and armor... but there's much more than meets the eye...

Sweet and naïve Hanato Kobato came to Earth on a mission to collect and fill a bottle with 'konpeito,' which appear after healing a person's heart that is suffering. Kobato collects these because it is her wish to go to a certain place. Despite her strangeness, Kobato turns out to be well-suited for this mission as her heartfelt sincerity in helping others earns her the love and admiration of everyone she meets. However, she is not allowed to fall in love with anyone whose heart she heals.
[Written by MAL Rewrite]

[From Tokyopop]:

Chun Hyang is the feisty young daughter of the village shaman and a master of the martial arts. When a tyrannical warlord threatens harmony in her village and abducts one of her friends, Chun Hyang vows revenge and sets off on an adventure that would become a legend.

The story is incomplete and it looks like it will not con.

Sakura Kinomoto was just an average 4th Grader - loved P.E., hated math - until one day, while looking through her father's library, Sakura found the Clow, an enchanted book designed to hold a set of magical Clow Cards. But when Sakura opened the book, it was empty. Talk about disasters!! Keroberos, the Creature of the Seal, emerged from the cover of the book and told Sakura the cards must be returned to the book. "If the cards aren't in the book, they come to life and do evil!" Kero formed a contract with Sakura making her a Cardcaptor and together with Sakura's best friend, Tomoyo, they embark on a mystical journey to capture all the Clow Cards before the Cards can wreak chaos and destruction