Joe is an extremely upbeat, excitable, considerate and loyal person. He is easily embarrassed when others misinterpret him and is sensitive to how people perceive his appearance. Like Sara, Joe puts in all his efforts to help the group succeed in the puzzles. He consistently convinces the group to believe in Sara and her abilities and generally places most of his trust to her. Though he is described as gaudy by Reko Yabusame and has a small habit of saying the wrong things at the wrong time, Joe is genuinely kind hearted and sensitive to others' feelings.

Although not academically one of the smartest in the group, he does provide occasional insight, such as his suggestion of a traitor among the participants. Despite that, Joe wants to find and believe in the good in others, even as he has his own doubts. 

To go more in-depth on his voice:

Jou is the epitome of Best Friend characters. He teases and gets teased, he cares about his friends an incredible amount, he’s just. Perfect. I can’t even describe him, he's just. Best Boy.

His voice should be warm and inviting, he needs to sound genuine. Even when he’s scared or upset, he tries his very best to put on a good face & ease the feelings of those around him. He’s a bit awkward, he’s very ‘innocent’ (he thinks people/guys[?] who kiss on the first date are monsters), and he is always looking out for the people closest to him & doing whatever he can to support them, especially in their moments of weakness. He may not think he’s the smartest or coolest kid in class; in fact, he sees himself as a ‘class clown’. But he’s very observant, he picks up on people’s feelings, and he wants to believe the best in people. He is the kind of friend who would go to the ends of the Earth for you, and you would do the same for him.