Nagito first comes off as a polite, friendly, and easygoing, yet somewhat insecure boy. Hajime Hinata even mentions that his bright smile is very comforting. He was the only one that stayed with Hajime while he was unconscious, and expressed concern for his well-being, even after Hajime told him to go away. Though friendly with everyone, he is mostly interested in spending time with Hajime and can be quite clingy, and as a result, Hajime considers him a little annoying and not the most reliable, but still thinks he's a kind person.

Nagito attempts to be the team's conflict mediator and a poster boy for optimism, often encouraging others to be hopeful and to cooperate, however, he isn't taken very seriously. Hiyoko Saionji makes fun of him and considers his dramatic pep talks about hope and friendship embarrassing and tiresome. He is generally quite submissive and has a self-deprecating attitude, even agreeing with Hiyoko and the others' snide remarks.