Ron is very passionate about solving mysteries. He possesses many skills and qualities needed to be a detective, e.g. he has outstanding deductive abilities and an excellent memory. However, Ron is quick to anger, and his fixation on cases makes him apathetic to everything else, standoffish and rude to other people, and easily bored when he has no cases to solve. Although he hated people even as a baby, Ron still cares about other people's lives. Thus, when he lost his detective license after the Bloody Field Trip Case and was branded a murderer, Ron became depressed and spent the next five years in isolation.

After Ron meets Totomaru Isshiki, he gradually begins to change and warm up to others, though he still likes using people for his own gain. 

Moreover, Ron has various idiosyncrasies. For example, Ron lies down next to corpses and "talks" to them, swearing that he will be their avenger, while he examines them. He does this to pay them his respect. He also likes to disguise himself when he accompanies Toto on cases, and sing "Kamo-Kamo" when he is happy. According to Kiku, Ron has had a "crazy" personality since before his expulsion.