Japan's electronic book market gained about ¥10 billion in sales last year to reach ¥57.4 billion and is expected to exceed ¥130 billion in five years, a research company said Thursday.

According to Impress R&D, a Tokyo-based information technology research firm, sales in fiscal 2009 overwhelmingly came from e-books for cell phones — ¥51 billion — while ¥6 billion was spent on content for computers.

Comic books, or "manga," for cell phones have been leading the growth, but new types of e-book readers, including smart phones and Apple's iPad tablet computer, are expected to see dramatic growth over the next few years, said Masahiro Kitagawa, an expert on the e-book industry and an executive of Impress Holdings Inc., which owns Impress R&D.