Abstract
As e-books have been becoming common, the market for digital textbooks also has been expected to grow rapidly. In this paper, we introduce our experience of developing interactive e-books with Unity3D, and the result of user's experiment of using the books. The e-books are targeted to the lower grades in elementary schools, and they are a series of a fairy tale story with educational information on flat tide. They support rich user interactions such as dragging and clicking objects and rich media including 3D animations, videos, pictures, and augmented reality. We separate educational information from the main story in order to meet some incompatible issues among story, education, and user interaction. We conducted user experiments with twenty four 4th grade students and 95.8% (23 from 24) of them liked the e-books. They also thought the e-books would help them study about flat tide and sea creatures in there.