Rōdō no Yoroi-san is a humanoid figure distinguished by his grey or silver armor. He operates the job reception booth where small creatures, including the main trio, sign up for daily tasks like weeding, hunting, or factory work. His duties involve assigning jobs, distributing wages, and diligently patrolling the area to monitor newly appearing monsters, assessing their potential threat to ensure the safety of the creatures under his oversight.

Despite his blunt and professional tone in workplace interactions, an underlying care for the creatures' well-being is evident through his patrols and careful management of hazardous assignments. He pursues weight training as a personal hobby, utilizing equipment such as ab rollers, though he keeps this activity discreet.

He maintains close friendships with two other armored figures: Pochette no Yoroi-san, a crafter of accessories, and Ramen no Yoroi-san, a ramen shop owner. The trio frequently socializes outside of work, including gatherings like picnics. His patience is occasionally tested by certain creatures, notably Momonga, whose loud demands for attention or food prompt direct admonishments to lower the volume.