AFS

AFS is an archive format used in Persona 3, Persona 4 and Persona 3 Portable. Its primary purpose is housing multiple ADX files. It is succeeded by AWB.

PuyoTools
PuyoTools can extract from and create new AFS archives. You can download a build here. The recommended settings are:
 * Compress Archive: No
 * Block Size: 2048
 * AFS Version: 2
 * Has Timestamps: Yes