The Anime Lad
Fourth grader Sakura Kinomoto finds the mysterious Book of Clow and reads the name of one card aloud. The cards scatter into the wind. Keroberos, their guardian, appoints Sakura to recover them, despite her limited experience with accidental magical releases. Her friend Tomoyo and rival Syaoran join an adventure that now fits between school days.
Super Eyepatch Fox
Open the Book of Clow. Speak one name. Watch a set of magical cards escape across town. Sakura is a fourth grader who has just become responsible for finding them again. Keroberos gives her the assignment, while friend Tomoyo and rival Syaoran ensure the recovery will not be a solitary job.
Gigguku
Sakura finds one strange book, says one name, and suddenly magical cards are flying everywhere. What a perfect doorway. She is still a fourth grader, but now Keroberos expects her to collect every card she released. Add loyal Tomoyo and rival Syaoran, and the adventure already has friendship, friction, and a wonderfully clear mission.
Father's Basement
The collect-the-magical-cards structure is simple and openly episodic. That clarity is useful. Sakura caused the problem, Keroberos gives her the job, and Tomoyo and Syaoran complicate what could have been a repetitive solo task. The premise leaves plenty of room for school life without pretending a fourth grader has stopped being one.