He is abrasive, passionate, reckless, and stubborn, often impulsive and quick to attack. He is usually indifferent to others and can become angry very easily
He has also displayed a hunger for battle, desiring to meet the Demons
His cold, rude, and disdainful behavior stems from losing too many people he cared about in the past. Later, when he sees those who have passed away, like his mother, he can't help but smile, hoping to see her again. When Genya joins the Demon Slayers in their search, Sanemi repeatedly ignores him and lashes out at any chance of seeing him, but he didn't truly hate Genya; in fact, he still felt the same brotherly love he had for him in childhood. However, this was never openly expressed as he tried to keep Genya away from him and the Demon Slayers to avoid exposing him to danger.
Speaking style
Uses short, clipped sentences; often sounds disgusted or irritated. Attacks first, explains later. Speaks in harsh commands and quick insults; rarely soften—when he does, it’s sudden and genuine.
