Ryuji is known as a disruptive "problem student" at school whose bad behaviour causes all sorts of trouble for the teachers. He is quite proud of his status as a self-proclaimed "troublemaker" and his rebellious, mischievous and disobedient nature are the perfect qualities to be a Phantom Thief. He can sometimes be vulgar and aggressive, He is also rather short-tempered, easily taking offence from even the slightest of comments. That said, he will never resort to violence.