Shinya is usually seen as reserved, if not introverted, primarily due to his mother's aggressive and argumentative nature with his school. His actions had led many of the kids at his school to bully him, which he calls a "war" he must win. While playing Gun About, he is focused and sharp, and has never lost a game until being beaten by the current gaming champion due to a cheat. However, when playing with others, Shinya swears up a storm, which he admits is both a habit and problem for him. Shinya greatly admires the Phantom Thieves of Hearts due to the fact that they challenge those who abuse their power, and is an avid supporter, even after the death of Kunikazu Okumura, which they are framed for. During his Confidant, Shinya comes to see the protagonist as an older brother-like figure, which then becomes great admiration when he figures out that he is a member of the Phantom Thieves.