Bringing Characters to Vitality:Enhancing Credibility of Original Characters in Narrative Works by making the OC a Generative AI agent

This study examines how generative AI can transform original characters (OCs) into interactive agents that improve character believability in design contexts. We propose a human–AI co-creation workflow that integrates dialogue, image, and context modalities, stabilizing style and behavior through structured prompts and expert feedback. In a mixed-method evaluation with expert creators (n = 5) and audience participants (n = 20), the approach increased perceived realism and emotional authenticity, while psychological complexity changed little, indicating the need for longer-horizon design. Dialogue contributed most to credibility, with context reinforcing coherence and images showing limited gains. We distill design principles for cross-modal alignment, style stability, and progressive complexity, offering a practical path to scalable, collaborative character design and more engaging interactive experiences.