Katsura appears to be wholly focused on what Kunikida told him two years ago, to the point of almost being obsessed. He is intelligent, having planned ahead with regard to the bombs and their setup. His desire to destroy Kunikida is not driven by revenge, but his desire to get rid of Kunikida's ideal, as well as test it. He seems to consider himself weak, and much of his actions seem to indicate an inability to accept himself. Two years ago, he was arrested by Kunikida from the ADA.