Kirio Fanclub FC is a spin-off volume that expands the world of the main Kirio Fan Club series through two distinct sections. The first part consists of original side stories focusing on characters who received less attention in the main narrative, including the occult-obsessed Manda Mitsuru, the energetic underclassman Tashiro Seira, and other classmates and acquaintances. These chapters explore their personal perspectives, daily routines, and hidden emotions, filling in gaps left by the main story. The second part is a tribute anthology featuring short manga by a variety of guest artists, each offering their own creative take on the characters and setting. The volume as a whole deepens the reader’s understanding of the ensemble cast while celebrating the series through the lens of fellow creators.