The Japanese concept of "Bunri" fusion, or the fusion between the human science and the natural science, was considered with its similarity to the multi-disciplinary approach based on the experience of "Yaoyorozu" project. Further consideration in terms of its elements and the approach in the context of human-centered design suggested (1) the desirable combination of necessary disciplines and (2) the management model for the development of devices and systems. In the latter proposal, a new approach using the scenario database was proposed as one of the best solution to minimize the gap between the human science and the technology, thus to develop the product with high level of usability.