Files like these are often discussed as "lost media" or digital artifacts. They represent a specific period in the evolution of the internet when localized Japanese content began to find a global audience through unofficial sharing channels.
: The AVI (Audio Video Interleave) format was the standard for high-quality video compression during the heyday of peer-to-peer (P2P) sharing networks like WinMX and Winny. Cultural and Technical Context -Queen8- Moe Kitahara . .AVI
The filename typically follows a naming convention used by niche online distributors or "circles" (creative groups). Files like these are often discussed as "lost