Unifying Sakura Taisen, Demon Slayer and JuJutsu Kaisen Canons

For Suburban Senshi purposes, Demon Slayer and its canon can be said to originate Sakura Taisen's and JuJutsu Kaisen's; when the forebears of the Imperial Assault force fought evil with just their bodies and their swords in the Sengoku area and before, they did so as Demon Slayers, who later evolved their techniques to what we see today. Since they seem to have forgotten for a time that men could also wield spirit power, it's possible they diverged from the main school of Demon Slayer training.

JuJutsu Kaisen, on the other hand, represents a divergence from Sakura Taisen canon; like the Demon Slayers of old they became "private" Demon fighters who still have ties to the government separate from those of the Imperial Assault Force, but whom are governed by their founding clans above all else.