Sojiro is serious and a bit cold to the protagonist in the beginning, begrudgingly taking him in as a favor to a friend. Like many characters in the beginning of the story, he is cautious of him due to his probation, even stating that he will do very little if the protagonist gets himself into trouble. However, the longer the protagonist lives with him, Sojiro slowly builds trust in him and even begins teaching him to make Leblanc's signature coffee and curry. He also begins to joke around with the protagonist more, seeing that the protagonist is not a delinquent as the probation makes him seem like. Sojiro is a very smooth talker and often charms women with choice words, even stating that he was "quite the ladies man" in his youth.