Set after the events of Devil Summoner 2: Raidou Kuzunoha vs. King Abaddon, with Raidou continuing his role as the Capital's protector working in the Narumi Detective Agency. The plot begins when normal people start to summon demons at the cost of their lives; with the demons coming out from their insides and a young girl currently under the protection of Raidou is targeted by the organization behind the normal humans summoning demons.