A Kallego side story manga honestly sounds really cool. Just imagine the possibilities! Not just young Kallego, but young Opera! And young Balam as well! Those three were all together at school, Opera being more of a bully and Balam being more of an only friend to Kallego. I feel like those three are pretty much confirmed, but there could be other teachers as well!
What was the Demon world like years before Iruma came into the fold? Will we actually see Delkira? What was Sullivan like? Were there any differences in the way school was taught? Will we get more context behind Momonoki and her crush on him? Seriously, there's a lot of questions, and they're probably not all gonna be answered, but this doesn't make it any less exciting!
But damn.
Iruma has truly become a franchise. It truly was the little manga that could, and seeing it grow in popularity and sales on both sides of the pond has been incredible. It's definitely become somehing I look forward to, and new chapters are always quite some fun! I'm really grateful to everyone involved with this.