Giyu always wears a stoic and unbothered expression on his face. However, he has a reserved personality and a very strong sense of justice with no tolerance towards those who don't know their own limitations and throw away their lives.After he was turned into a demon in a battle with one of the uppermoons,he began to rush at everyone and tried to bite even Tanjiro,but he was taken to Tamayo in time and,for the sake of safety,they chained one of his hands to the bed in order to treating him.