In the midst of a tranquil Edo period, Heizou Hasegawa, known as the 'Devil,' wields his blade to vanquish malevolence. Embracing his duty as the top protector against crime and fires, Hasegawa, during the Tenmei era of 1783, leads the charge in safeguarding the domain's peace. Feared for his relentless pursuit of the most nefarious wrongdoers, he earns the infamous moniker of Devil Heizou.