Azure Striker Gunvolt: Fleeting Memories (陽炎のメモリア, Kagerou no Memoria) is a side story series written by Gunvolt scenario writer Toshiaki Tai and narrated by Moniqa's voice actress Moemi Otaka. It debuted on Aug 10 2014 as a segment on INTI CREATES' YouTube program Interactive Wave. An English translation by Matt Papa is found on their website.
Since the release of Part 20 on Dec 28 2014, and the last Interactive Wave program being held on Feb 15 2015, the series has received no further updates and appears to be postponed indefinitely.
The plot of Fleeting Memories can be divided into two parts with little relation.
Parts 1 through 5 focus on narration about the Azure Striker Gunvolt world, and Copen and Mytyl's father, Dr. Kamizono. His mindset which would influence Copen, the nature of his work, the nature of Adepts and Septima, and the origins of the Sumeragi Group are shown in detail seldom seen elsewhere in the series. This part of the story ends with the death of Dr. Kamizono, his assistant, and the destruction of the facility they worked at as a certain Azure Striker test subject's restraints fail at the beginning of an experiment.
Parts 6 through 20 are based around the normal human siblings Rei and Miu. Their lives were forever changed by an encounter with a mysterious Adept serial killer known as Raptor, who suddenly killed their parents while the family was out for Rei's 9th birthday. The side story also details their encounter with an Adept named Himeshiro. This story ends with the cliffhanger of Himeshiro talking to Rei about Raptor.
The side story received an overall positive reception from fans of Gunvolt. Many readers considered the story to be better than that of the Azure Striker Gunvolt game. After widespread support from fans, Matt Papa, the translator of Fleeting Memories, revealed that Toshiaki Tai was developing a "season two" of the side story. The release date for the continuation has yet to be confirmed.