The story follows the adventures of Mikie Okamine and Origami Tobiichi. An explosion occurred near Tengu city, thinking that a spirit appeared, the AST hurried to the place only to find a girl named Ashley Sinclair. The next day, Ashley enrolled to the same school Tobiichi and Okamine are attending.
Later in the story, it is revealed that Ashley is a former member of SSS (Special Sorcery Service, the British equivalent of AST). Together with Leonara Sears and Cecil O'Brien, they hijacked three of the latest CR-units the Ashcroft series. To stop the three from rampaging Tobiichi and Okamine used the remaining Ashcroft units #1. Alice for Origami and #5. Cheshire Cat for Mikie. The battle wasn't that easy as they discover things about the Ashcroft series.
Sometime in the past SSS ace wizard Artemisia B. Ashcroft decided to leave them for DEM believing that the advanced technology of the company will help her achieve bringing forth world peace. Unfortunately, Artemisia's memories were stolen from her which left her brain dead. The Okamine Heavy Industries miraculously produce the Newest CR-Units, The Ashcroft, with Artemisia's memories as part of its core program. It is said to provide enough power alone to defeat a spirit.
The AST soon found out that the Ashcroft instead of providing superior power against spirit it is designed to counter other CR-Unit of other wizards. The units once worn by a wizard creates an imprint which makes it useless for others to use making it solely for the first wearer.
With with Ashcroft #2. Jabberwock Cecil is capable of creating Anti-Territory fields, Leonora's Ashcroft #3. Lion is capable of heavy bombardment and Ashley obtaining Ashcroft #4. Unicorn she excels greatly with melee combats the trio easily overwhelms the AST. Fortunately Tobiichi's Ashcroft #1. Alice can protect her from other CR-Unit's Territories and Okamine's Ashcroft #5. Cheshire Cat is fitted with an AI navigation system called Bell, a self-healing function and a pair of armor-piercing claws called Kitty Fang.
As the battles ensue, Ashley recognizes navigation system Bell as her "old friend" to which no one knows why.