Koharu Hōen commands the Monster Development Department for the rival evil organization Black Lore. She once collaborated with Doctor Hajime Sadamaki as a peer before defecting to Black Lore, now driven to demonstrate her scientific dominance over Sadamaki through the monsters engineered for her faction.

Black Lore enforces oppressive corporate policies akin to a "black company," demanding relentless workloads while denying overtime pay and disregarding employee welfare. This cutthroat environment clashes with the comparatively principled operations of Agastia, where Sadamaki and Kuroitsu work. Koharu's leadership and departmental tactics starkly reflect Black Lore's exploitative ethos.

Her assistant is Elbakki, a catgirl monster designed by Black Lore, who regularly engages with Agastia's Wolf Bete. Koharu strategically deploys Elbakki during field operations and cross-organization collaborations.

Narratively, Koharu acts as a foil to Agastia's Monster Development Department, personifying the divergent methodologies and corporate values between the rival entities. Her department's creations perpetually challenge those developed by Kuroitsu and Sadamaki, though definitive outcomes of these contests remain unrecorded.