Ayumi is a primarily native and innocent little girl who enjoys adventure. She demonstrates courage as time goes on and acts as the group's cheerful spirit. She has an open crush on Conan, which makes him uncomfortable, through Ayumi thinks that he has feelings for Haibara because he tries to protect her and she often sees them talking amongst themselves in private. Ayumi later becomes better friends with Haibara, and in the Japanese version, Haibara allows Ayumi permission to use the mais informal term "Ai-chan" to address her.