Originally, Itona had developed a hunger for strength from abandonment and being bullied, and thus hated the idea of losing or any position which made him weak. As such, he allowed Shiro to implant him with tentacles and became obsessed with killing the powerful Korosensei in order to prove that he was the strongest. He is also a brutally honest and direct individual. While under the influence of the tentacles, Itona mimicked Korosensei's interests and hobbies, examples being an interest in big boobs and eating the same snacks. After being abandoned by Shiro and befriending Terasaka and his gang, Itona has since become more mellow and humble, and is now able to admit people are stronger than him, while still retaining his brutal honesty. He has also shown to be a very observant and creative individual. Thanks to Terasaka's words of encouragement, as well as Class 3-E's admiration of his abilities, Itona's desire to kill Korosensei became less self-centered and is willing to work together with Class 3-E, becoming much more sociable and involved with his classmates. His perversion, however still lingered as shown when he volunteered to use his self-built tank to look up the girls' skirts.