Hattori Hanzo operates as a shinobi directly serving Motoyasu Matsudaira. He consistently wears all-black ninja garb, masking his face during missions. His personality reflects ruthless efficiency and emotional detachment, especially during assassinations; he dismisses negotiations unless they present unambiguous strategic advantages for Motoyasu without risk. Yet, he respects skilled opponents who evade his assaults, acknowledging their prowess. Hanzo philosophically opposes poison, yet contemplates its use against Sagara Yoshiharu when conventional tactics fail. He demonstrates subtle humor through calculated actions, like deliberately withholding intelligence about Nobuna Oda's advancing army from Yoshimoto Imagawa by dismissing it as merely "a dragon," unworthy of reporting. His loyalty belongs solely to Motoyasu, not the wider Imagawa command. His narrative actions begin with reconnaissance at Okehazama, identifying Yoshiharu as an Oda spy and launching relentless attacks with shuriken and blades. When Yoshiharu persistently evades, sustaining only minor injuries, Hanzo considers violating his anti-poison principle. Yoshiharu ultimately convinces him to stand down by arguing their escape serves Motoyasu's long-term interest, facilitating her eventual defection from the Imagawa. Accepting this minimal-risk rationale, Hanzo permits their retreat. During the Okehazama battle sequence, Hanzo observes Yoshiharu leading Oda troops toward the Imagawa camp in a storm. He intentionally mischaracterizes the formation as a natural phenomenon when subordinates try to alert Yoshimoto, enabling the undetected Oda assault. This tactical deception highlights his prioritization of Motoyasu's future over immediate Imagawa loyalties. His interpersonal dynamics reveal further complexity: labeling fellow ninja Chidori as "cute" triggers intense jealousy in her comrade Sukezo. His combat skill and strategic acumen earn him respect among both ninja communities and military leadership of the era.