Akashic Line (アカシックライン) was an online game created by Jyotaro Amagi as a testbed for his Real Digitalization technology. It was released for only three months as a closed beta. The game succeeded in digitalizing Tokio Kuryuu, an unsuspecting Double Ware, for a few seconds.

After the beta ended, data for the game remained on the internet. Eventually benevolent AIDA found their way into the game and inhabited the body of an event NPC called AIKA, who Amagi had subconsciously based on his aunt Ayaka Amagi.

Data for the game was later analyzed by Geist and Saika Amagi, and the latter retrieved AIKA as a key to finding her cousin.

Community content is available under CC-BY-SA unless otherwise noted.