Leon is a passionate, hot-blooded young teenager. He often slacks off from studying and baseball practice; however, his baseball skills were never diminished due to his status as Ultimate Baseball Star. Leon is also very determined to change his current title to Ultimate Musician. In Leon's Free Time sequence, the reason for that determination is revealed: to win a heart of a girl that he happened to meet at the hair salon. Later, Leon himself states that he somewhat missed playing baseball; something that he used to do every day since he was young. He even invited Makoto to play baseball with him once they get out of their current situation.

During the main story, Leon is shown to be easily intimidated and agitated, such as when Makoto spends time with him for the first time and he thinks it's a trap to kill him, or during the first class trial when he asks and finds out who Sakura Ogami is. When he becomes nervous or intimidated, Leon tends to smile awkwardly, often the right corner of his mouth stretching farther.

In the official artbook, Leon is described as an optimist who wants to get better at everything he does. He is also mentioned to be a player, and he had a new girl with him every few days. He is always flirting with girls and he's single-mindedly focused on studying "the secret of success with the ladies". He's also mentioned to be into pure-hearted girls.