Professor Sadamaki leads the Monster Development Department for the secret organization Agastia, engineering monsters to counter heroes such as the Divine Swordsman Blader. He perpetually wears a high-tech visor obscuring his eyes, reinforcing his detached and cool persona. Though highly intelligent and technically skilled, his relaxed approach causes habitual procrastination and missed deadlines, forcing his assistant Tōka Kuroitsu to manage urgent fixes and corrections.

Unbeknownst to either, his younger brother Kenji Sadamaki—Blader’s civilian identity—fights against Agastia while the professor spearheads its anti-hero operations. This hidden familial conflict layers their interactions with complexity, though both remain ignorant of their opposing roles.

Removing his visor triggers a stark personality shift: he grows expressive and intensely focused, revealing unexpected diligence and heightened competence beneath his typical aloofness. This transformed state seldom surfaces.

He navigates leadership challenges by mediating between Akashic’s whimsical demands for "cuter" monsters and Megistus’s pragmatic oversight, frequently pivoting projects mid-stream. Wolf Bete’s abrupt redesign into a feminine form exemplifies such interventions. Amidst shifting directives, he adapts to departmental budget constraints and resource limitations.