The Pottermore Shop will soon offer eBooks in Japanese. They will be available in the latest EPUB format — EPUB3.
From the Pottermore Insider:
The Harry Potter eBooks will be available in Japanese this summer – at the same time the Pottermore Shop will be launching in Japanese. Further announcements regarding the Shop opening date will be made in due course.
At the moment, prices have not been announced for the Japanses ebooks. This teaser page was also launched.
In related news, it looks like the Pottermore Shop will be launching sometime in the future in a mobile format.
We currently have no mobile site for the Shop, although we will be launching this in due course.
If you’re a Harry Potter fan who’s ever wanted to learn Japanese, this would be a perfect opportunity for you!