This paper presents an AI-based character expression analysis tool and evaluates its usability and reliability through user research. Using an analysis extraction model based on Contrastive Language Image Pretraining (CLIP), the tool quantifies character expressions by gender and age from image data and includes visualization components that effectively display these results to general users. User research results revealed that participants understood the visualized analysis results and recognized the tool's overall usability, but they also highlighted the need for visualizations that included more detailed demographic categories and contextual information. While confidence in the AI-based gender and age models was moderate to low, there was no opposition to their use. The tool code, benchmarking, and user research data are available on GitHub.