Jean Sénat Fleury is a prolific author, and his ability to write many books can be attributed to several factors:

1. Passion for history and research: Fleury's books often focus on historical events and figures, indicating a deep passion for research and understanding the past.

2. Strong writing discipline: To produce multiple books, Fleury must have a rigorous writing routine, allowing him to manage his time and energy effectively.

3. Organization and planning: Fleury likely has a systematic approach to researching and outlining his books, enabling him to work efficiently and complete manuscripts in a relatively short time.

4. Expertise in multiple areas: Fleury's books cover various topics, such as Haitian history, Japanese history, and international relations, suggesting a broad range of interests and expertise.

5. Collaboration and co-authorship: It's possible that Fleury co-authors or collaborates with other writers, researchers, or historians, allowing him to share the workload and produce more books.

6. Use of technology and writing tools: Fleury likely leverages modern writing software, digital resources, and research tools to streamline his writing process and stay organized.

7. Dedication and commitment: Above all, Fleury's productivity is a testament to his dedication to sharing knowledge and stories with the world.

Keep in mind that writing multiple books requires a tremendous amount of effort, discipline, and creativity. Fleury's accomplishments are a reflection of his hard work and passion for sharing his ideas and research with others.