Ayumi is a primarily naive 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, even dreaming about marrying him, which makes him uncomfortable. At the same time, 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 she allows Ayumi permission to use the more informal term Ai-chan to address her. When on a case, Ayumi often makes simple observations that help lead to progress and resolution.