As someone who puts themselves down a lot and normally comes off as weak and shy, Shuichi is a boy who doesn't have much confidence in himself and claims he isn't accomplished enough to be referred to as the Ultimate Detective. Putting his timid personality aside, he's also calm and serious about many situations, and is also a polite teenage boy. At times he can call others out for their behavior when he's gained a stronger attitude, but other than that he mostly stands out for his submissive and shy personality.

Shuichi's voice can either be higher pitched if you're aiming for a resemblance of the Japanese voice, or a mid tone voice if your preferences are aimed for the English voice. Both voices need their soft tone - Shuichi normally doesn't speak so loud.