A top-secret spy, Stewart is very careful and secretive. However, he is not without sentimental emotions. His assignment as a teacher at Station Square Elementary School, in particular, changed him very much. At first, he was bored with his new assignment, but in time, he grew accustomed to it and felt an obligation to protect his students, like a real teacher and guardian. He took great care of his students, eventually to the point that he willingly disobeyed important orders from his superiors in order to protect his students.