Hiroomi Souma, a 20-year-old assistant chef at Wagnaria, presents a disarmingly serene facade with his short dark blue hair, grey eyes, and ever-present closed-eye smile. Beneath this amiable exterior lies a shrewd tactician who manipulates coworkers by weaponizing their secrets, uncovered through calculated observation, trickery, or rifling through personal belongings. Preferring strategic wordplay and leveraging embarrassing revelations to evade responsibilities, he frames his actions as playful amusement rather than outright malice.

Guarded about his past, Hiroomi’s secrecy becomes a liability when Aoi Yamada fabricates distress, painting him as a bully in Popura Taneshima’s eyes. Despite his irritation, he begrudgingly tolerates Yamada’s persistent attachment, including her use of “Onii-chan.” His meddling in Jun Satou’s romantic pursuit of Yachiyo Todoroki often earns him physical retribution, though his awareness of Yachiyo’s violent history—such as her disposal of men threatening Kyouko—cements his role as an information broker.

Mahiru Inami’s androphobia-induced aggression renders her immune to his schemes, forcing him to interact via phone from a distance. He deduces her crush on Souta Takanashi through meticulous observations like her daily hairclip changes, but his attempt to exploit this fails spectacularly when she silences him with violence. Armed with a digital camera to capture compromising moments, he balances his blackmail endeavors with unspoken ethics, such as withholding explicit confirmation of Satou’s feelings from Yachiyo.

His name, blending “Hiro” (command) and “omi” (servitude) with the surname “Souma” (mutual horse), mirrors his duality. While his manipulative core remains unchanged, his dynamic with Yamada exposes rare vulnerability. Interactions with colleagues oscillate between detached scheming and curious investment in their lives, underscoring a paradoxical coexistence of detachment and engagement.