He is precautious and rigorous. He cares about his mission and prepared. He takes his Job very seriously and hates people who don’t. Even Makima the head of the Public Safety called Kusakabe as reliable and best bodyguard that exist. When Makima finds out that Denji's existence is revealed in the media, she orders Kusakabe along with other Devil Hunters, to keep him safe from any assasinationts, by other forgein government Agents who might want to kill him. Has a contrat with the Stone Devil.